Longer wheel studs for newer style aluminium wheels.

[Edmond]

I bought the newer style 8 Lug wheels from a Chevy Avalanche.
Problem now is that the current wheel studs are to short, so I'm looking for longer wheel studs.
Been browsing the Dorman site but can only find the 2-5/32 lenght studs.
I need longer than that.

http://www.dormanproducts.com/gsearc....623+chevrolet

Anyone that can help me with the right partnumber?

Thanks in advance.

[BrentRS1985]

http://www.summitracing.com/search/d...pe/wheel-studs

Start here and narrow down the search results with the links on the left hand side of the page. You don't have to buy the part from summit, but at least you can find the part number you're looking for.

[john]

try these. Long time no see on the board Edmond.
http://www.summitracing.com/search/d.../9-16-18-in-rh

[Edmond]

Yes it's been a while John. Been lurking around though, never been away long, just not posting much

Anyway, thanks for the links guys.
Looks like there are not long enough 9/16-18 thread wheel studs with the right size knurl
There are so many different sizes of these wheels studs I'm almost going crazy.
Maybe I should go to metric style wheel studs. Looks like these are the only ones with the right length.

[68shortfleet]

Take a look at this PDF
http://www.billavista.com/atv/PDF_In...%20Catalog.pdf

I am looking at 610-347. The knurl diameter is 0.002" larger, that should not be a problem. Almost 3" long too.

Good luck

[Edmond]

Wouldn't the shoulder length on that one not be a problem?

Thanks for the link by the way, great pictures of the wheel studs.
Better than on the Dorman site.

[71Dually]

I'm currently working to mount Alcoa classics on a 71 C/30 dually and doing the same research.

Research for my 71 dually with a full float Eaton indicate 2 different length studs for the front and rear. I believe the C/20 will have a similar Eaton full float rear end albeit may have shorter studs for a single rear wheel.

I'll probably go with Dorman 610-194 in the rear for the full float hubs. The stud is 3-17/32" long and the shoulder length should be fine for the rear hub.

The rears are the only ones I've currently acquired sample studs for and approaching a final decision on.

Tentatively I'm looking at the 610-182 studs for the front hubs and those are one of the 2-5/32" lengths you indicate. These are supposed to be the same studs currently on my truck but I have not yet checked the front stud standout or tried to mount the Alcoa's on them. My front studs most likely need to be changed but I just haven't looked at them yet with so much going on with other areas of my truck.

My research on the Dorman site for my C/30 indicate that all the front studs for 1971, 73, 76 & 84 are 2-5/32". According to Dorman the 1971 rear studs are 3" in length and the 73 is 3-15/32" and the 76 & 84 are 3-17/32".

Then there are the M14-1.5 metric sizes. 89 & 95 show the fronts at 2-9/16 (M53.5) & the rears at 3-9/16 (M90.5).

You may want to consider Ford studs in your choices also. The 96 F350 has 2-7/16" studs with a 5/8" shoulder in front and a 3-9/16 with a 15/16" shoulder in the rear. Both these studs are 9/16-18.

Your link comes up with 9/16-18, 6.23 knurl and Chevrolet results only. In my research I simply used the 9/16-18 thread size in my search to bring up all the choices and then manually sorted thru the all results. I also did this same type search for the M14 metric studs as they don't make two piece flanged wheel locks in a 9/16-18 size.

I send thank you's out to BrentRS1985, john and 68shortfleet for the additional resource links. I can use these for finding studs to mount my Alcoa classics.

Edmond, my Dorman site research with part numbers follows, hope it helps. Good luck with your new wheels.

1971 Chevy C30 DRW (9/16-18)
Front:
Application Summary: Chevrolet 1999-71, GMC 1999-71
Length (In): 2-5/32 (2.1562)
Shoulder Length (In): 0.5 (1/2)
Knurl Diameter (In): 0.623 (5/8)
Dorman Part # 610-182 (10 piece box)
Dorman Part # 610-182.1 (1 piece bag)

Rear:
Application Summary: Chevrolet 1999-71, GMC 1999-71
Length (In): 3 (3.00)
Shoulder Length (In): 1.0625 (1-1/16)
Knurl Diameter (In): 0.622 (5/8)
Dorman Part # 610-189 (10 piece box)
Dorman Part # 610-189.1 (1 piece bag)


1973 Chevy C30 DRW (9/16-18)
Front:
Application Summary: Chevrolet 1999-71, GMC 1999-71
Length (In): 2-5/32 (2.1562) +0.0
Shoulder Length (In): 0.5 (1/2) + 0.0
Knurl Diameter (In): 0.623 (5/8) +0.0
Dorman Part # 610-182 (10 piece box)
Dorman Part # 610-182.1 (1 piece bag)

Rear:
Application Summary: Chevrolet 1974-72, GMC 1974-72
Length (In): 3-15/32 (3.46875) +0.46875
Shoulder Length (In): 1.0625 (1-1/16) +0.0
Knurl Diameter (In): 0.62 (5/8) +0.0
Dorman Part # 610-193 (10 piece box)
Dorman Part # 610-193.1 (1 piece bag)


1976 Chevy C30 DRW (9/16-18)
Front:
Application Summary: Chevrolet 1999-71, GMC 1999-71
Length (In): 2-5/32 (2.1562) +0.0
Shoulder Length (In): 0.5 (1/2) +0.0
Knurl Diameter (In): 0.623 (5/8) +0.0
Dorman Part # 610-182 (10 piece box)
Dorman Part # 610-182.1 (1 piece bag)

Rear:
Application Summary: Chevrolet 1999-75, GMC 1999-75
Length (In): 3-17/32 (3.53125) +0.53125
Shoulder Length (In): 1.3125 (1-5/16) +0.25
Knurl Diameter (In): 0.621 (5/8) -0.001
Dorman Part # 610-194 (10 piece box)
Dorman Part # 610-194.1 (1 piece bag)


1984 Chevy C30 DRW (9/16-18)
Front:
Application Summary: Chevrolet 1999-71, GMC 1999-71
Length (In): 2-5/32 (2.1562) +0.0
Shoulder Length (In): 0.5 (1/2) +0.0
Knurl Diameter (In): 0.623 (5/8) +0.0
Dorman Part # 610-182 (10 piece box)
Dorman Part # 610-182.1 (1 piece bag)

Rear:
Application Summary: Chevrolet 1999-75, GMC 1999-75
Length (In): 3-17/32 (3.53125) +0.53125
Shoulder Length (In): 1.3125 (1-5/16) +0.25
Knurl Diameter (In): 0.621 (5/8) -0.001
Dorman Part # 610-194 (10 piece box)
Dorman Part # 610-194.1 (1 piece bag)


1989 Chevy C30 DRW (M14-1.50)
Front:
Application Summary: Chevrolet 2002-88, GMC 2002-88
Length (In): M53.5 (2.1063) (2-7/64) -0.0501
Shoulder Length (In): 0.5314 (17/64) +0.0314
Knurl Diameter (In): 0.6299 (5/8) +0.0049
Dorman Part # 610-331 (10 piece box)
Dorman Part # 610-331.1 (1 piece bag)

Rear:
Application Summary: Chevrolet 2002-88, GMC 2002-88
Length (In): M90.5 (3.563) (3-9/16) +0.563
Shoulder Length (In): 1.2795 (1-9/32) +0.217
Knurl Diameter (In): 0.6251 (5/8) +0.0031
Dorman Part # 610-333 (10 piece box)
Dorman Part # 610-333.1 (1 piece bag)


1995 Chevy C30 DRW (M14-1.50)
Front:
Application Summary: Chevrolet 2002-88, GMC 2002-88
Length (In): M53.5 (2.1063) (2-7/64) -0.0501
Shoulder Length (In): 0.5314 (17/64) +0.0314
Knurl Diameter (In): 0.6299 (5/8) +0.0049
Dorman Part # 610-331 (10 piece box)
Dorman Part # 610-331.1 (1 piece bag)

Rear:
Application Summary: Chevrolet 2002-88, GMC 2002-88
Length (In): M90.5 (3.563) (3-9/16) +0.563
Shoulder Length (In): 1.2795 (1-9/32) +0.217
Knurl Diameter (In): 0.6251 (5/8) +0.0031
Dorman Part # 610-333 (10 piece box)
Dorman Part # 610-333.1 (1 piece bag)


1996 Ford F350 DRW (9/16-18)
Front:
Application Summary: Ford 2007-67
Length (In): 2-7/16 (2.4375) +0.2813
Shoulder Length (In): 0.625 (5/8) +0.125
Knurl Diameter (In): 0.623 (5/8) +0.0
Dorman Part # 610-300 (10 piece box)
Dorman Part # 610-300.1 (1 piece bag)

Rear:
Application Summary:
Length (In): 3-9/32 (3.28125) +0.28125
Shoulder Length (In): 0.9375 (15/16) -0.125
Knurl Diameter (In): 0.677 (43/64) +0.055
Dorman Part # 610-303 (10 piece box)
Dorman Part # 610-303.1 (1 piece bag)

[Edmond]

Thank you 71Dually for your very impressive research.
Yes I did search for other brands also and indeed the Ford ones looked like the best choice.
I was only afraid that the shoulder length would perhaps give a problem.
Anyway I think it will finally turn out on 610-300.
Thanks again you guys!

[71Dually]

Groeten Edmond,

I fiddled a bit with the rear wheel studs today.

Catching up on what I've done:

1) About 6 weeks ago I acquired a full set (front & rear) of factory wheel studs from a 1996 Ford F-350 Dually. Dorman's replacement part #'s are 610-300 & 610-303

2) Two weeks ago I acquired new Dorman wheel stud #'s 610-193 & 610-194. (73 & 76 Chevy rear dually studs)

3) Last week I acquired a used factory rear wheel stud set from a 1982 P30 Step Van when I pulled some RPO JB8 14BFF rear brakes for an Eaton brake conversion. These studs are Dorman's replacement part # 610-194. I also acquired an additional set of factory rear studs (Dorman # 610-189) from a a pair of 1971-72 C30 Eaton dually hub/drum assemblies. A big shout out and huge thank you's go out to Hoopers Rear End Exchange in Sun Valley, CA for the over the top great deal on these original Eaton HO72 hub/drum assemblies. Anthony & Ryan really know their stuff and are super folks to boot. A real asset to the truck culture community.

4) A couple days ago I mocked up my Alcoa's on the original factory wheel studs on my 71 C30 and confirmed the studs are to short.

5) Today I assembled the 14BFF drums on the Eaton hubs with the 82 P30 studs and mocked up an Alcoa wheel.

6) Today I compared the rear 96 Ford F350 studs (610-300), the 82 Chevy P30 rears (620-194), the 71 Chevy C30 rears (610-189) and the new Dorman # 610-194 to each other. I have previously compared the new Dorman studs (620-193 & 610-194) to each other. Due to the shorter shoulder length on the 193 I have decided to use the 194 so the 193 was not compared to the factory studs.

7) Today I also compared the factory P30 studs to the Dorman 610-194 replacements. The Dorman's are a tiny bit shorter than the factory studs by about 1 to 1-1/2 threads. I didn't mic them out, just did a real quick comparison to see if they were actually the same length. They were not.

I have only worked on the rear studs at this time but should get to the fronts in the next few days. I would presume the difference in the Ford studs on the rear would also be the same on the fronts but have yet to confirm the front stud information.

My Observations:

The front and rear Ford studs have an undersize shoulder prior to the start of the threads. On the factory rears studs I have this shoulder measures .225" (just under 1/4") which affects the useable thread length of the studs. Dorman's pictures show this same shoulder so I would presume the over all effective thread length is 3.05625" or only .050" over the stock Chevy rear studs on my application. Being such Dorman's # 610-303 Ford stud will not work on my rear dually application.

I was going to install one Ford stud in the Chevy drum/hub assembly but was met with a strong resistance to it going into the assembly. Not wanting to oversize my hub stud holes I did not install it.

The 14BFF brake drum mounting flange thickness measures 0.377" verses the Eaton's flange at 0.165". The original Eaton drum/hub assembly also has an oil slinger on the inside of the drum that measures 0.045". This equates to a total effective Eaton flange thickness at 0.210". The 14BFF drum flange is effectively 0.167" (just under 3/16") thicker than the Eaton's. This will effect the stud standout from the wheel mounting surface by the same distance.

I installed the factory 1982 P30 studs (Dorman # 610-194) and torqued the Alcoas to 90 lbs. ft. The torque spec is 140 lbs. ft. but the 90 was fine for mockup. The P30 studs are acceptable for use with just barely 3 threads exposed using the specified Alcoa factory flanged lug nuts. That is plenty for safe full lug nut engagement. If these same studs are used with the original Eaton drums then approximately an additional 3 threads would be exposed thru the lug nut for a total of 6. That I believe is more than enough exposed thread length to pass even NASCAR's & NHRA's strict tech standards. Note: The Alcoa rear dually wheel installation calls for a steel wheel mounted on the inner dually wheel. That was how the stud length with the Alcoa was checked.

My Conclusions:

The factory P30 studs will be fine length wise in my application. I still want to install the slightly shorter Dorman 194 replacement to see how it works. If it is to short I will acquire a Chevy Dealers replacement and compare it to the Dorman for any difference. If the Chevy replacement matches the slightly longer used factory P30 stud I have and not the shorter Dorman then I will use the dealers parts. If the Dorman is acceptable then I will go with them. If I feel the Dorman replacements are a thread short than I'll probably re-knurl and re-zinc plate the used P30 studs I have and use them. I would really prefer to use a new part though.

My Modus Operandi:

I am only acquiring single samples of the Dorman parts until I determine exactly what I will run. I don't want to install 32 new studs at $2.25 a pop to find them unacceptable and then not be able to return them as they had been installed and would thus be "used" parts. I'm pretty anal and articulate and do not do things like "that should be good" or "that's good enough" With my families and communities populaces safety and my liability on the line I go with nothing less than "that's right."

Since a photos worth a 1,000 words here are some for documentation:

Definitely both front and rear original C30 wheel studs are to short for the Alcoa's:

Front:


Rear:



Rear Factory Stud comparison: 1971-72 Chevy C30 (left), 1996 Ford F350 (center) & 1982 Chevy P30 (right):



Rear stud effective thread length comparison of 96 Ford F-350 Dually (left) & 71-72 Chevy C30 Dually (right):



Eaton Brake Drum Mounting Flange thickness:



14BFF Brake Drum Mounting Flange thickness:



Brake Drum flange comparison: 14BFF (top) Eaton (bottom):



14BFF brake drum, Eaton HO72 hub and dually Alcoa Wheel installation with P30 stud thread exposure:




In conclusion Edmond, I don't know if this rear C30 dually stuff will help with your C20 and newer Chevy Avalanche wheels. If you do have an Eaton Full Floating axle on your C20 (I think you may) then it may in fact help. However, I do think my findings show that the Ford studs effective thread length is not what it may appear to be. I believe that this effective thread length should be considered when deciding to use the Ford type 610-300 replacement Dorman studs.

Several things I have not done yet that I feel are pertinent is to mic the Alcoa mounting thickness, inner steel wheel thickness, stud standout, Eaton hub drum mating to wheel mating flange thickness and to check the actual lengths of the different uninstalled wheels studs with a micrometer for comparison to the Dorman specifications. All of these items very well could affect possible stud standout differences in DRW and SRW applications.

Tomorrow I am spending the day looking into a JB8 front brake conversion on my 71 dually but I will get back on the front studs very soon. I will post my findings here on the several above mentioned items and the front C30 hub/stud findings as soon as they are concluded.

Cheers.

[71Dually]

Got a few edits and a few additions in bold blue:

Originally Posted by 71Dually

6) Today I compared the factory rear 96 Ford F350 studs (610-303), the factory 82 Chevy P30 rears (610-194), the factory 71 Chevy C30 rears (610-189) and the new Dorman # 610-194 replacements to each other. I have previously compared the new Dorman studs (610-193 & 610-194) to each other. Due to the shorter shoulder length on the 193 I have decided to use the 194 so the 193 was not compared to the factory studs.

and

Originally Posted by 71Dually

However, I do think my findings show that the Ford studs effective thread length is not what it may appear to be. I believe that this effective thread length should be considered when deciding to use the Ford type 610-300 replacement Dorman studs. The front Dorman 610-300 replacements are 2-7/16" long but with the 1/4" undersize leading shoulder the effective thread length is actually only 1/32" longer than the 2-5/32" length of the stock Chevy stud (610-182). This equates to about a half a thread and a minimal effective thread length gain. Doing the math it works out to actually only being 2-3/16" overall of useable wheel stud.

Hope this helps.

[Edmond]

Thanks again for your very informative post.
Yes this helps indeed.
I finally decided on 610-346 for the front and 610-347 for the rear.
They are harder to find here in The Netherlands so it will take a while before they are here.
Will post pictures later when they are on the truck.

Groeten vanuit Nederland!

[71Dually]

Greetings Edmond,

Congratulations on finding suitable wheel studs for your truck. I'm posting the following front wheel stud information for you and other forum members seeking the same.

Regarding the front wheel studs I've researched various Chevy/GMC Truck Master Parts Catalogues.

Per the catalogues my 1971 C30 dually calls for a front wheel stud 1-29/32" long (part #3997956) The catalogues also show that this same #3997956 is the correct front stud for a C20 from 71-86. The 73-86 C30 duallies call for a 2-1/8" long front wheel stud (part #334388).

The factory front wheel stud information conflicts with Dormans application data for wheel stud #610-182. Dorman's catalog shows all 71-99 Chevys use the 2-5/32" wheel stud. While the 610-182 stud will work in a 71-72 application if Dormans catalogue is actually used to determine the original 71-72 factory stud length then the information will be incorrect and misleading. The reason I believe Dorman uses the longer 73 and up #610-182 2-5/32" length stud for the 71-72 application is that since it fits the 71-72's it is cheaper to supersede the original stud length rather than retool for and market a 1/4" shorter stud.

But this supersede can lead to confusion as it makes it appear that the 610-182 stud will not increase the factory stud standout for alloy wheels on 71-72 models. In reality, 610-182 will actually increase stock stud standout by 1/4" (0.265" or 6.73mm) on 71-72 models.

I have acquired a factory #334388 wheel stud from an 82 P30, a factory #3997956 from my C30 and a Dorman 610-182 from a local parts house.

Comparative stud length measurements:
71-72 factory front stud #3997956 measures: 1.909" (48.49mm)
73-86 factory front stud #334388 measures: 2.173" (55.19mm)
Dorman front stud #610-182 measures: 2.173" (55.19mm)

My Alcoa's have a 0.5735" (14.56mm) mounting flange. Alcoa's mounting instructions specify a minimum 1.5" stud standout for mounting a single front dually wheel. The standout with the Dorman #610-182 and the 73-86 factory stud #334388 is 1.3875" or 0.1125" short of what is specified. To achieve the specified standout would require a 2-9/32" stud. I mounted the wheel and do achieve full lug nut engagement with approximately 1-1/2 threads exposed outside the lug nut. With the required 1.5" standout I would achieve 3-1/2 threads exposed. While I would prefer to have the 3-1/2 threads exposed I can live with 1-1/2 threads as the lug nut is fully engaged and will torque correctly. If I do locate an 1/8" longer stud I will use that.


Regarding rear C20 wheel studs the rear stud of the 71-72 C20 SRW is different than the C30 DRW. According to the master parts catalogue there are 2 different applications for the C20 depending on the rear axle type. The Dana axle uses part #3995888 and the Chevy axle uses part #3988537. Part #3988537 (Chevy Axle) is 2-1/2" long and part #3995888 (Dana Axle) is 2-1/8" long according to the hub bolt chart in the Chevy parts catalogue illustration section.


Here are some pictures.

Chevy catalogue lug bolt charts (2)
#1:


#2:


Front Wheel Stud camparision, Factory 71-72 part #3997956 (left), Factory 73-86 part #334388 (center) and Dorman #610-182 (right):


Mounted Alcoa wheel showing front wheel stud thread exposure:


Mounted steel wheel thread exposure (showing difference between stock 71-72 studs vs. 73-86 stud):


Hope this all helps with mounting alloy wheels on 71-72 trucks. I do believe I have found the information and wheel studs I need to mount my Alcoa's.

Edmond, please, let us know how everything works out and post up some pictures of the mounted wheels on the studs when you get everything set-up.

Thank you.

[Edmond]

Well the ordered bolts (610-347) for the rear did not fit the hub.
Major bummer.
Will have to find out what kind I do need.
Hopefully al your info will help me enough in finding the right bolts.

Have no pictures yet, Truck is in the shop that's doing the work for me.
Will keep you updated.

[Edmond]

Picture is of the front wheel. (Still with the old wheel)
I guess it might be a bit to long but that can be easily fiksed.
The other picture is of the original bolts, front and rear together with the new Dorman bolt.
I will order new bolts for the rear.
Probably Dorman 610-194

[LSUMurse]

Hey 71Dually, please take this with the jovial intent it was meant to be taken in but, we've got this national debt problem that needs some researching done. Holy crap, man. You are serious.

[Edmond]

Front wheel is on including the cap.
Luckily the wheel studs were not to long.

[Edmond]

Finally the rear wheel studs are fitted.

Looks good, well at least I think so

[71Dually]

Edmond,

I think it looks great too!

Those rear disc brakes also look awesome.

What studs did you end up using?

Thank you for the topic, I'm sure this will come in helpful to the membership seeking to accomplish an alloy wheel install on their 67-72 trucks.

Again everything looks awesome, great job.

Greetings LSUMurse, jovial intent all good and warmly received as such. Yeah, you hit the nail directly on the head, most times I can be pretty extreme with the research. As far as the national debt, them folks assigned the task can probably use the practice so I'll leave it up to those assignees. While I certainly can balance a checkbook and have dabbled in forensic accounting, I'll stick with 67-72 Chevy truck research for now.

Cheers,
71Dually

[Edmond]

Thanks

For the rear I ended up using 610-194.
And in the front 610-347.

Disc brakes on the rear wheels makes it so much easier working on them.
I hated the big drums, changing the brake shoes was a nightmare

Thanks again for your research.

[LSUMurse]

Originally Posted by 71Dually

Greetings LSUMurse, jovial intent all good and warmly received as such. Yeah, you hit the nail directly on the head, most times I can be pretty extreme with the research. As far as the national debt, them folks assigned the task can probably use the practice so I'll leave it up to those assignees. While I certainly can balance a checkbook and have dabbled in forensic accounting, I'll stick with 67-72 Chevy truck research for now.

[davepl]

Looks like it's all covered here above, but just in case: you need the tapered shoulder lug nuts, and then you need a stud that works with them. And if you did not already have 9/16" studs you will need to drill out the holes.

If you go that route I highly recommend you do it with the drum ON and 2-3 lugnuts lining it up, then drill the others, then finish up. It's surprisingly hard to get 8 lugs aligned properly.

Use a hydraulic press, which means removing the hub. Pulling them through with a lug nut is a no-no we've all done once but shouldn't.

I had to use a spacer to get the Dana60 to clear the centercaps, which meant even longer studs. Unlike the photo, though, I used only one spacer.

[JennCat]

This thread has been an excellent read. I have reviewed it with the intent of extrapolating information useful to my 70 C30 and steel rims. However, most catalogs I have perused seem to have a cut off at 71. They seem to be divided into 68-70 then 71+. Not knowing which change occurred to cause the difference in lug studs between 70 and 71, I am uncertain that it is wise to attempt to extrapolate.

Moreover, I am thinking that I may want to lose the steel rims in the future but trying to avoid buying new lug studs and nuts (again) when I do. Nuts, ok, but pressing in new studs, not unless I have to.

I am getting set up to do brakes and it would be an ideal time to swap out the studs. I am yet undecided as to use 9/16 or 5/8 because I am uncertain how the choice might effect my options of rims later.

I may need to get the calipers out and pull one of the drums to decide which shoulder length and overall length I want to go with.

Also, I noticed Dorman wasn't exactly clear on a few things and from the information provided by 71Dually, maybe getting out the calipers is the best way to go.

[71Dually]

Greetings JennCat,

You have indicated:

Originally Posted by JennCat

I am uncertain that it is wise to attempt to extrapolate.

Hey, it's always good to extrapolate, that's how ya learn stuff. I extrapolate all the time, or is that ramble on? Yeah, it's the ramble on one. I do quite a bit of that with all the stuff I extrapolate.

I was curious about the weight rating on your truck so I went back to your C30 Disc Brake Conversion topic and see you've indicated you have 8 lug front hubs.

This indicates to me you have a 10,000lb. GVW rated truck.

Regarding the wheel studs, the 5/8"-18 studs are used on the 14,000lb. GVW C30's and are to large for potential wheel applications on your smaller GVW rated 8 lug truck.

There is a topic in the forum indicating the 14,000lb GVW trucks have 5 lug studs on the front and 10 lug studs on the back. The topic which contains this information is http://67-72chevytrucks.com/vboard/s...d.php?t=147662. While that topic is regarding C50 trucks the information is relevant to 14,000lb. GVW C30's as both use the 11,000lb rated rear axle. This same axle uses the larger 5/8" lug studs. The information about stud count is in post #14 of the linked topic. The lug size information is out of the Chevy parts catalog and the Dorman website catalog.

The 14,000lb. GVW wheels have 10 lug holes so they can mount on either the 5 or 10 lug hubs. They would also have larger lug holes corresponding to the 5/8" studs. 8 lug dually wheels would have lug holes that correspond to the 9/16" studs used on those applications.

A note on Chevy dually wheels. I don't know if you know this but they are hub-centric wheels. This means the center hole on the wheel aligns to the hub to remain centered. This hub-centrics main purpose however is to actually support the weight of the vehicle and its load. The hub-centric on a Chevy wheel is 4.56" if I recall correctly. Dodge and Ford hub-centric dually wheels have a larger hole, not sure what exactly, maybe 4.75" or something like that but they are definitely larger.

Dodge and Ford wheels use the same lug pattern as Chevy and their wheels will bolt to your hubs but they are not correct. The hub-centric's are to large and the wheel will not remain centered or support the vehicle or its load. An improper hub-centric puts all the weight pressure of your truck and it's load on your lug studs. Under this condition the lug studs will certainly fail and you will lose a wheel. So please, break out the calipers (they are your friend) and check that center hole dimension when you are looking at wheels for your truck.

Regarding the cut off in the catalogs, 1/2" studs were used up thru 1970 and starting in 1971 they were 9/16"-18. That's the reason.

I'd stick with the 9/16 studs. You'll have to ream your rear hubs for them unless you can get a 71-72 hub set that originally came with the 9/16" studs. Be careful though, don't get the later 73 up rear hubs as those are 14 bolt hubs, the bearings and the offsets are different. They are incorrect for, and will not fit your Eaton axle. Please note I also used the term "ream" instead of "drill out." Reams are much more accurate then drill bits when it comes to hole sizes. Use a ream to enlarge the hubs lug stud hole to retain the close tolerance that pressed fit lug studs require.

We've met on the previously mentioned C30 Disc Brake conversion topic. I'm still working on the posting I've indicated in that topic I will do. It will contain what I believe will be a comprehensive writeup about what parts to use to convert your 70 C30 to front disc brakes. One of the things that will happen when you do the conversion is you will end up with the later 9/16-18 lug studs that are long enough to accept the aluminum wheels as those studs are native to the 74-91 parts you will use for the conversion.

I'm polishing up my research, proofreading and editing the text and figuring out the pictures. It's funny though, the info I just posted above about the 14,000 GVW lug studs is contained in the conversion writeup I'm doing as it is relevant to the parts search and donor vehicles. That was how I found and remembered that post in the first place.

So there ya go. I haven't forgotten about your disc conversion and will get the info up ASAP. Should be within the next few days.

Till then,
Cheers

[JennCat]

Once again, much thanks for the information 71, it is a tremendous help. At present, I intend to swap out all 32 lug studs and nuts, while in process of doing (drum) brakes. I am still learning about the disk brake conversion and am going to check my drum brakes erstwhile. Not ready to convert to disk just yet.

The hub centric info is great and right on time. I really appreciate the response. It was necessary because I have been getting conflicting opinions on the steel rims I just put on my truck. The rims are set to accept 9/16 studs and are presently riding on 1/2 inch. They are hub centric and do fit. The conflicting info I am receiving is whether I actually need the clamp rings. 71, I really like the flanged through nuts you put on your truck and that is the way I would like to go. But some have told me I should make clamp rings and use beveled lug nuts for proper torque. My friend (Richard) can machine a set of clamp rings for me but he tells me I need to know the depth of the beveled area to machine the proper seat depth for contact.

So I am uncertain whether to have a set of rings made and use the beveled or to go with the flanged (which I like). Either way, it looks like I''m going with the 9/16-18.

Moreover, the idea of using a ream to enlarge the holes in the hubs and drums is premium. Thanks for the advise.

[71Dually]

JennCat, thank you for your praise.

Run the flange nuts as long as you can attain good contact on the wheel with the flange.

The nuts I'm running are the original factory pieces. One picture in my posts in this topic does show the larger Alcoa flange nuts. I have a whole set of those I will be running with my Alcoa wheels when I get them ready.

There is not a huge difference between 1/2" and 9/16" only a 1/16" so I don't think it will be an issue with the wheels set up for 9/16 studs. I would just center the lug stud in the wheel hole before torquing the nut. As long as ya got plenty of nut flange meat contacting the wheel it should be fine. The nuts and studs actually only hold the wheel to the hub. When you install a wheel torque the wheels to spec and then check them at about 100 miles. Thereafter recheck them every 500 miles. That routine is called for in the Chevy service manual.

Chevy put the rings and conical nuts on the next generation round body trucks. I don't know if they started in 1973 or if they were introduced later but they did use them. If desired that may be a source to get some rings so you won't have to custom make them. One thing I'd watch for on the Chevy rings is the seating surface of the 1/2" conical lug nut on the rings larger 9/16" conical contact area. To little of a contact area between the two and the lug nut could pull thru the ring leaving you without the proper, if any, clamping force.

I don't use the rings because the factory didn't put them on my truck in the first place, so why do I need them? My trucks 43 years old and there are no signs that the wheels have fallen off yet. The rings also take up valuable real estate on the pre 1973 lug studs and move the nuts much closer to the end of the studs. You may actually not attain full thread engagement with the rings. If you don't get full thread engagement between the nuts and the studs this will cause problems with proper torque and may strip your fasteners.

I'm positive the rings are partially the reason the lug stud length was increased in 1973. I know the 73 and up 14BFF drum flange is thicker. I don't know if the hub flanges are a different thickness. My 14BFF hubs are buried in the garage or I'd pull out my trusty calipers and do a comparison. The addition of the rings and the thicker drum flanges combined would, by itself, dictate longer studs.

Everyone having different opinions is normal and so are their different solutions to the same problem. I usually take it all in and then figure out what I think is best. The one opinion that weighs the most in my mind however is the manufacturer. I always seek out the manufacturers data and follow it. I've been junk yarding for nearly 40 years now. Believe me, I have seen lots of different "opinions" by mechanics who previously worked on the cars before they entered the yard. Some of those opinions actually put the cars there in the first place.

Not really trying to stick my head in your fox hole but... if it's feasible do at least the rear drum brake swap. Why? I'll tell you my story. I bought all new shoes, hardware, wheel cylinders etc... to do the rear brakes on my Eaton. Spent about $100 on everything. This was all before I pulled my drums. So I've got everything torn down, cleaned and reassembled but before I put the drums on I take them to be checked. They were out of spec and with no replacements available I was forced to use them as is. Well one drum is out of round and the shoe still goes click, click, click with every single revolution of the drum. So with the hard earned cash I spent, the knuckles I busted, and the grease under my fingernails I still didn't have optimum brakes.

I've got about 2,000 miles on them now and while I will run them longer the thought of spending good money on bad bothers me. I could have put that money into the 14BFF brake parts but didn't so now I have to double spend and double work. Life is to short to have to do double work and moneys to hard to come by to have to spend it twice. But that's just my opinion.

Please post some pictures of your truck. I'm interested in seeing the rear end to verify it is in fact an Eaton and not a later 14BFF swap. Maybe start a build thread where you can post lots of pictures and tell everyone about your truck, reveal your plans and show off your progress.

Good to see you again and keep turning wrenches.