Got some new wheels: Boss 338's in 20x10 and 20x8.5 - Page 4 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Hickup pickup · 07-10-2009, 05:43 PM

Mod to dust cap

Hickup pickup · 07-10-2009, 05:47 PM

Just about there

SCOTI · 07-10-2009, 05:55 PM

That's a sweet burb BTW.

Hickup pickup · 07-10-2009, 06:21 PM

Thanks SCOTI !

Dinos63 · 07-10-2009, 09:22 PM

it looks killer,worth the work rob

chuckmc8 · 07-12-2009, 06:31 AM

I found a retailer on the web that had this info posted. I just Googled "BOSS 338 fitment guide" and chose one. Although these are 18" I think we determined that the hub area is the same on the 18 and the 20". I just cut and pasted the info below. Notice that the vehicle that I chose was a 71 Blazer, It didnt give a 5 lug 71 truck as an option. These have "gauranteed fitment" I guess that no one has tried it on a truck rotor tho. It does have the other models listed that these are suppose to fit in a 5x5 lug pattern. Any of these GM rotors interchange with our trucks?
OEM tires: 225/75-15 (717x225mm). Bolt pattern: 5x127 (5x5). Offset: -10 to 10 mm. Tires up to 757x265mm. Rims up to 23x9.5".
Browse:
What Fits

Styles
Specs

TIRES
DIRECT FIT package. [ Fitment Guarantee] See package options See what else fits
Back
BOSS 338 B
18x9.5, Bolt Pattern (PCD) 5x127 (5x5), Offset (ET) -4mm
Gray/Machined Lip, $169.00 each.
5x127 (5x5) bolt pattern, offset -4 is considerable for:
( 18x9.5 size can be unsuitable for certain models/years/trims )
Buick: Roadmaster
Cadillac: DeVille
Chevrolet: 1500 2WD truck Astro Blazer 2WD C10 C1500 454SS truck Impala Laredo 2WD Suburban 1500 2WD Tahoe 2WD Van 5 lug
GMC: 1500 2WD truck Jimmy Full Size 2WD Safari Savana 1500 Suburban 1500 2WD
Lincoln: Continental Mark III

I also looked for Astro van rotors for a pic-notice the step in the hub that is similar to the machined version that was modified for the 'burb

big_al_71 · 07-12-2009, 08:49 PM

are these the same wheels?

chuckmc8 · 07-12-2009, 09:04 PM

I think so Al.

chuckmc8 · 07-13-2009, 09:59 AM

I think that I know whats going on here with the rotors. After 1988 all 5x5 rotors are 'stepped' on the hub like the Astro van rotors that I posted the pics above. i just looked up 88 & up applications for C/10, Van, burb and so on and all are stepped. prior years are not.
So the kwestion (my kue doesnt work on my keyboard) is there a way to run the later model rotors (88 & later) (ed:I have since found out there isnt)
I am running an 1986 crossmember with 2 1/2" drop spindles.

BTW, The coys dont fit w/o mods either. Here is a thread for reading with good photos on the coys. The 71-87 rotor hubs are the problem...after 88 I beleive the BOSS 338 or the Coys just bolt on w/o any mods
http://67-72chevytrucks.com/vboard/s...d.php?t=300737

UPDATE-I went to AutoZone and asked them to put an 86 rotor and a 88 rotor on the bench so that I could compare them- the 88 and later hub (and thus the spindle) is 1" shorter than the 87 & earlier stuff. That explains how the BOSS center cap clips in as designed. There would be ample room on the 88 and up rotor.
here is a 1988 & up rotor

The only other thing to check is if 88 & up spindles (with these smaller rotors & brake components)
would work on 67-72 suspensions.....if not, the grinding/lathe turning proceedure will be the only way to run these wheels.
Maybe useless info, but it doesnt cost anything to gather......and maybe help someone else

BossHogg69 · 07-13-2009, 10:12 AM

Quote:

Originally Posted by chuckmc8

So the kwestion (my kue doesnt work on my keyboard)

I'm not poking fun here, but for some reason I couldn't stop laughing, not because your 'kue' doesn't work, but because you just kept on truckin' without it! that's awesome!

mentlmidget · 09-12-2009, 07:18 AM

test

I typed a nice reply before, and it wouldn't post. I will edit this if it works.
about time.

I have a set of 20x8.5 boss 338 rims on my 86 c10 with 5x5 (127 mm x5) bolt pattern. The ONLY mod I had to do was a slight denting of the dust cap. Since my truck has a drop spindle and drop spring setup on the front, they do hit the inner fenderwell on tight turns and big dips in the road, nothing major. A little sheet metal fabwork and the problem should be solved (getting set up for bags anyway). My only suggestion would be to buy 20x10 for the rear. The rear is to short and the track from the rear to the front looks odd. The rear tires are inset compared to the front. Possible corrective behavior would be to:
#1- install a wider rear ($$$)
#2- install spacers (YUCK)
#3- install 20x10 for rear

I like the last option, but will wait until I have the rear bag mounts and setup installed.

aggie91 · 07-13-2009, 01:42 PM

Quote:

Originally Posted by chuckmc8

The only other thing to check is if 88 & up spindles (with these smaller rotors & brake components)
would work on 67-72 suspensions.....if not, the grinding/lathe turning proceedure will be the only way to run these wheels.
Maybe useless info, but it doesnt cost anything to gather......and maybe help someone else

This works but you have to change a few things. The 88 up lower ball joint is larger in diameter in the part that presses into the lower a arm. It is the same diameter as the ones for a 3/4 ton lower a arm. The upper ball joint mounts the same as the 71-87 upper ball joint so that the upper a arm will work. You would need to change to a 3/4 ton lower a arm and use teh 88-up ball joints, otherwise it works...

thebrown83 · 07-13-2009, 12:06 PM

actually these don't fit on the 88-98s either. My friend bought 18x9.5s for his 97 silverado and they would not go all the way over the front hub to sit flat. He had to return them and get boss 335s which look good also and actually fit.

69gmcshorty · 07-18-2009, 02:22 AM

SUBSCRIBED. I am fairly new to the site but my career is in wheels and tires. I have a boss dealer that we "deal" with and i am in love with the wheels. I will have a chat with him tomorrow if their open on saturdays and see what he has to say about future upgrades.

**nlped** · 07-14-2009, 05:25 PM

Hhhhmmm! I actually have a pair of 18x9.5 338's sitting next to me that I am using on the rear of my '87 and am waiting on the 18x8's to come in. I know they won't fit directly onto my set up, but I'm gonna try "fabbing" up a sealed hub/slide on rotor type hub. We shall see!

**lolife99** · 07-15-2009, 07:48 AM

Does anyone have Wilwood or Baer brakes/rotors on their truck? I would be interested to know if any aftermarket disc brake rotors would work.

greystoke · 07-15-2009, 08:52 AM

I have baer on mine, if you want to provide me the measurement from the back of the boss wheel to where the cap mounts and the diameter I will check for you. I don't run these wheels but have an interest in them.

Dano

**lolife99** · 07-15-2009, 09:23 AM

That would be great greystoke.
I actually took some measurements the other day.

On the wheel itself:
From the wheel mounting flange to the opening (where the chrome boss cap snaps in) is 2-5/8" tall.

The rotor center hub height is 2" tall with the dust cap removed.
(these are auto parts 5-lug rotors purchased locally)

At the end of the rotor hub (where the dust cap presses on) the diameter is approximately 2.800". This is using my cheap plastic dial calipers that I have at home.

The diameter of the opening of the wheel (where the center hub dust cap sticks thru) is only 2.410".

If you could measure your Baer rotors center hub "height" (minus the dust cap),... and a diameter of the center hub, (right at the base of the dust cap),... that would be great!

greystoke · 07-15-2009, 09:29 AM

I will check this out, I'm at work right now. My first thought is that there will still be a fitment problem but I've been wrong before and will be again.

greystoke · 07-15-2009, 10:41 PM

ok lowlife99....I pulled the tire off and looked at the baer front hub. I don't have a fancy measuring deal so with a tape this is what I have.

From the face of the rotor ( where the wheel mounts ) to the hub edge is about 1 7/8"

Same spot to the end of the spindle nut is about 2 1/2"

The hub at the top is about 2 3/4" outside to outside.

The problem is there is a step at the base of the hub which is probably a tad over 3", it would seem the opening of the Boss 338 wheel would need to be machined a bit larger. that seems like a viable option.

**lolife99** · 07-15-2009, 10:51 PM

Thanks for checking. I appreciate all your effort.
Which Baer kit do you have?

greystoke · 07-15-2009, 10:58 PM

Baer GT

what do you think about machining the mounting flange hole a little bigger. I don't know if it's such a good idea.

**lolife99** · 07-15-2009, 11:49 PM

I would rather machine on the rotor,... but there is a step inside the wheel center,... that appears to be causing some interference. It will be awhile before I address these issues, but I will be looking at Wilwood's website to try to find out more.
Thanks again.

greystoke · 07-16-2009, 07:12 AM

then there's always the simple route of using a spacer. I feel once it cleared the step it would fit fine.

**lolife99** · 07-16-2009, 07:32 AM

I'm not using a spacer.
The 8.5" wheel with a 5.25" BS is perfect for me.
It would be easier for me to machine a disc rotor "style" hub,... that use a disc rotor "hat", that slides over a seperate hub.
Maybe the big brake kit from McGaughys.

07-10-2009, 06:21 PM	#4
Hickup pickup Registered User Join Date: Dec 2008 Location: Gilbert , Az Posts: 369	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 Thanks SCOTI ! __________________ 2-20, 2-21 whatever it takes!

07-10-2009, 09:22 PM	#5
Dinos63 chevy only Join Date: Sep 2006 Location: Phoenix, AZ Posts: 6,619	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 it looks killer,worth the work rob __________________ CHEVY ONLY... Nothin Else !

07-12-2009, 06:31 AM	#6
chuckmc8 It's alsways something..... Join Date: Nov 2008 Location: Douglasville GA Posts: 1,171	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 I found a retailer on the web that had this info posted. I just Googled "BOSS 338 fitment guide" and chose one. Although these are 18" I think we determined that the hub area is the same on the 18 and the 20". I just cut and pasted the info below. Notice that the vehicle that I chose was a 71 Blazer, It didnt give a 5 lug 71 truck as an option. These have "gauranteed fitment" I guess that no one has tried it on a truck rotor tho. It does have the other models listed that these are suppose to fit in a 5x5 lug pattern. Any of these GM rotors interchange with our trucks? OEM tires: 225/75-15 (717x225mm). Bolt pattern: 5x127 (5x5). Offset: -10 to 10 mm. Tires up to 757x265mm. Rims up to 23x9.5". Browse: What Fits Styles Specs TIRES DIRECT FIT package. [ Fitment Guarantee] See package options See what else fits Back BOSS 338 B 18x9.5, Bolt Pattern (PCD) 5x127 (5x5), Offset (ET) -4mm Gray/Machined Lip, $169.00 each. 5x127 (5x5) bolt pattern, offset -4 is considerable for: ( 18x9.5 size can be unsuitable for certain models/years/trims ) Buick: Roadmaster Cadillac: DeVille Chevrolet: 1500 2WD truck Astro Blazer 2WD C10 C1500 454SS truck Impala Laredo 2WD Suburban 1500 2WD Tahoe 2WD Van 5 lug GMC: 1500 2WD truck Jimmy Full Size 2WD Safari Savana 1500 Suburban 1500 2WD Lincoln: Continental Mark III I also looked for Astro van rotors for a pic-notice the step in the hub that is similar to the machined version that was modified for the 'burb Attached Images Last edited by chuckmc8; 07-12-2009 at 09:08 AM.

07-12-2009, 08:49 PM	#7
big_al_71 Registered User Join Date: Jun 2008 Location: South Florida Posts: 11,375	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 are these the same wheels? Attached Images __________________ Get your facts first, and then you can distort them as much as you please!!!!!. Sylvester's build thread >>>http://67-72chevytrucks.com/vboard/s...ht=big+rebuild

07-12-2009, 09:04 PM	#8
chuckmc8 It's alsways something..... Join Date: Nov 2008 Location: Douglasville GA Posts: 1,171	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 I think so Al.

07-10-2009, 05:43 PM	#1
Hickup pickup Registered User Join Date: Dec 2008 Location: Gilbert , Az Posts: 369	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 Mod to dust cap Attached Images __________________ 2-20, 2-21 whatever it takes!

07-10-2009, 05:47 PM	#2
Hickup pickup Registered User Join Date: Dec 2008 Location: Gilbert , Az Posts: 369	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 Just about there Attached Images __________________ 2-20, 2-21 whatever it takes!

07-10-2009, 05:55 PM	#3
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,025	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 That's a sweet burb BTW. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

07-13-2009, 09:59 AM	#9
chuckmc8 It's alsways something..... Join Date: Nov 2008 Location: Douglasville GA Posts: 1,171	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 I think that I know whats going on here with the rotors. After 1988 all 5x5 rotors are 'stepped' on the hub like the Astro van rotors that I posted the pics above. i just looked up 88 & up applications for C/10, Van, burb and so on and all are stepped. prior years are not. So the kwestion (my kue doesnt work on my keyboard) is there a way to run the later model rotors (88 & later) (ed:I have since found out there isnt) I am running an 1986 crossmember with 2 1/2" drop spindles. BTW, The coys dont fit w/o mods either. Here is a thread for reading with good photos on the coys. The 71-87 rotor hubs are the problem...after 88 I beleive the BOSS 338 or the Coys just bolt on w/o any mods http://67-72chevytrucks.com/vboard/s...d.php?t=300737 UPDATE-I went to AutoZone and asked them to put an 86 rotor and a 88 rotor on the bench so that I could compare them- the 88 and later hub (and thus the spindle) is 1" shorter than the 87 & earlier stuff. That explains how the BOSS center cap clips in as designed. There would be ample room on the 88 and up rotor. here is a 1988 & up rotor The only other thing to check is if 88 & up spindles (with these smaller rotors & brake components) would work on 67-72 suspensions.....if not, the grinding/lathe turning proceedure will be the only way to run these wheels. Maybe useless info, but it doesnt cost anything to gather......and maybe help someone else Attached Images Last edited by chuckmc8; 07-13-2009 at 11:42 AM.

09-12-2009, 07:18 AM	#11
mentlmidget Registered User Join Date: Jun 2005 Location: Fort Lauderdale, FL Posts: 30	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 test I typed a nice reply before, and it wouldn't post. I will edit this if it works. about time. I have a set of 20x8.5 boss 338 rims on my 86 c10 with 5x5 (127 mm x5) bolt pattern. The ONLY mod I had to do was a slight denting of the dust cap. Since my truck has a drop spindle and drop spring setup on the front, they do hit the inner fenderwell on tight turns and big dips in the road, nothing major. A little sheet metal fabwork and the problem should be solved (getting set up for bags anyway). My only suggestion would be to buy 20x10 for the rear. The rear is to short and the track from the rear to the front looks odd. The rear tires are inset compared to the front. Possible corrective behavior would be to: #1- install a wider rear ($$$) #2- install spacers (YUCK) #3- install 20x10 for rear I like the last option, but will wait until I have the rear bag mounts and setup installed. Last edited by mentlmidget; 09-12-2009 at 07:26 AM. Reason: more info

07-13-2009, 12:06 PM	#13
thebrown83 Registered User Join Date: Sep 2007 Location: Kingfisher OK Posts: 176	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 actually these don't fit on the 88-98s either. My friend bought 18x9.5s for his 97 silverado and they would not go all the way over the front hub to sit flat. He had to return them and get boss 335s which look good also and actually fit.

07-18-2009, 02:22 AM	#14
69gmcshorty Registered User Join Date: Jun 2009 Location: Eugene, Oregon Posts: 104	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 SUBSCRIBED. I am fairly new to the site but my career is in wheels and tires. I have a boss dealer that we "deal" with and i am in love with the wheels. I will have a chat with him tomorrow if their open on saturdays and see what he has to say about future upgrades. __________________ 1969 gmc swb 5/7ish drop, 350/th400, 20x8.5 F.20x10" R

07-14-2009, 05:25 PM	#15
nlped Senior Member Join Date: Jul 2009 Location: Hayden, Al. Posts: 4,148	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 Hhhhmmm! I actually have a pair of 18x9.5 338's sitting next to me that I am using on the rear of my '87 and am waiting on the 18x8's to come in. I know they won't fit directly onto my set up, but I'm gonna try "fabbing" up a sealed hub/slide on rotor type hub. We shall see!

07-15-2009, 07:48 AM	#16
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,699	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 Does anyone have Wilwood or Baer brakes/rotors on their truck? I would be interested to know if any aftermarket disc brake rotors would work. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

07-15-2009, 08:52 AM	#17
greystoke Registered User Join Date: Jul 2008 Location: Buckeye, Arizona Posts: 694	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 I have baer on mine, if you want to provide me the measurement from the back of the boss wheel to where the cap mounts and the diameter I will check for you. I don't run these wheels but have an interest in them. Dano



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07-15-2009, 09:23 AM	#18
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,699	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 That would be great greystoke. I actually took some measurements the other day. On the wheel itself: From the wheel mounting flange to the opening (where the chrome boss cap snaps in) is 2-5/8" tall. The rotor center hub height is 2" tall with the dust cap removed. (these are auto parts 5-lug rotors purchased locally) At the end of the rotor hub (where the dust cap presses on) the diameter is approximately 2.800". This is using my cheap plastic dial calipers that I have at home. The diameter of the opening of the wheel (where the center hub dust cap sticks thru) is only 2.410". If you could measure your Baer rotors center hub "height" (minus the dust cap),... and a diameter of the center hub, (right at the base of the dust cap),... that would be great! __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823 Last edited by lolife99; 07-15-2009 at 09:37 AM.

07-15-2009, 09:29 AM	#19
greystoke Registered User Join Date: Jul 2008 Location: Buckeye, Arizona Posts: 694	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 I will check this out, I'm at work right now. My first thought is that there will still be a fitment problem but I've been wrong before and will be again.

07-15-2009, 10:41 PM	#20
greystoke Registered User Join Date: Jul 2008 Location: Buckeye, Arizona Posts: 694	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 ok lowlife99....I pulled the tire off and looked at the baer front hub. I don't have a fancy measuring deal so with a tape this is what I have. From the face of the rotor ( where the wheel mounts ) to the hub edge is about 1 7/8" Same spot to the end of the spindle nut is about 2 1/2" The hub at the top is about 2 3/4" outside to outside. The problem is there is a step at the base of the hub which is probably a tad over 3", it would seem the opening of the Boss 338 wheel would need to be machined a bit larger. that seems like a viable option. Last edited by greystoke; 09-25-2009 at 10:54 AM.

07-15-2009, 10:51 PM	#21
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,699	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 Thanks for checking. I appreciate all your effort. Which Baer kit do you have? __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823 Last edited by lolife99; 07-15-2009 at 10:52 PM.

07-15-2009, 10:58 PM	#22
greystoke Registered User Join Date: Jul 2008 Location: Buckeye, Arizona Posts: 694	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 Baer GT what do you think about machining the mounting flange hole a little bigger. I don't know if it's such a good idea.

07-15-2009, 11:49 PM	#23
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,699	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 I would rather machine on the rotor,... but there is a step inside the wheel center,... that appears to be causing some interference. It will be awhile before I address these issues, but I will be looking at Wilwood's website to try to find out more. Thanks again. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

07-16-2009, 07:12 AM	#24
greystoke Registered User Join Date: Jul 2008 Location: Buckeye, Arizona Posts: 694	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 then there's always the simple route of using a spacer. I feel once it cleared the step it would fit fine.

07-16-2009, 07:32 AM	#25
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,699	Re: Got some new wheels: Boss 338's in 20x10 and 20x8.5 I'm not using a spacer. The 8.5" wheel with a 5.25" BS is perfect for me. It would be easier for me to machine a disc rotor "style" hub,... that use a disc rotor "hat", that slides over a seperate hub. Maybe the big brake kit from McGaughys. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823 Last edited by lolife99; 07-16-2009 at 07:38 AM.

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