38" tires/gear ratio - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1971 2wd · 04-29-2004, 12:05 AM

With 38" tall tires what gear ratio would work well??

Now I have 3.73 in 1/2 ton 72 blazer 4x4.

Don't kown if I should jump into doing this swap??

Heres my deliema:
Maybe getting 4.11 from 74 pick-up 4x4. The rear is 14 bolt and the front is DANA 60 flat top knuckle.
Includes Drive lines, complete from hub to hub (front) and drum to drum (rear).

He's calls it the heavy 3/4 ton.

The big plus he said he install it all for $500.00! (axles & labor)

Sorry if this seems to be a dumb A$$ question!!

The Dude · 04-29-2004, 12:23 AM

get the new axles. more strength, and $500 is than buying 2 new sets of gears plus install.

1969 GMC · 04-29-2004, 12:31 AM

dana 60 front axle wasnt introduced in GM trucks til '77. as far as i know, all dana 60's have flat top knuckles...at least all kingpin dana 60's.
it sounds like the front axle is actually a dana 44, which looks very similar to a dana 60. i'd be careful before i bought it. if you need to see pics of dana 44 vs dana 60, look in the link in my sig, and go to the photo album called "axles", you will find what you need there.

**JIMs70GMC** · 04-29-2004, 04:40 AM

Yep I believe only dana44 are refered to as having flat tops and 1975 is in the range of years for them. Does it have 4 u-bolts holding the axle to both springs total or only 3 and 2 studs?

2wdBlazer · 04-29-2004, 08:41 AM

I would jump on that 3/4 ton deal. I am currently running 3:73's until I can afford a 4:56 swap. It is really underpowered. I would get a minimum 4:11 gear.

1971 2wd · 04-29-2004, 09:29 AM

I probably wrong on what I said about DANA 60.

1969 GMC: I looked at the pics and they don't look like those at all. They are flat top.

JIMs70GMC: Yes there are 4 u-bolts holding the axles. Are you talking about the studs on the knuckle? If so there 3.

Oh I forgot to mention the guy also said they are the big wheel bearing HUB/ALXES.

Did they make 3/4 ton alxes that were DANA 44??

I wish my camera wasn't broken I would post some pics.

Thanks alot. Anymore? Keep them coming!!

Mudder · 04-29-2004, 09:30 AM

Yep you'll need at least 4.11's. That sounds like the heavy D44 with the big hubs. It fools a lot of guys. Still a good set of axles.

1971 2wd · 04-29-2004, 09:39 AM

Yeah, by looking at the front axle tub it look the same size of a 1/2 ton.

I thinking 4.11's will fine with a well built 350 or a 383 stoker.

BPB · 04-29-2004, 01:52 PM

Here ya go. Check out this out

**JIMs70GMC** · 04-29-2004, 08:11 PM

On a dana60 there's one u-bolt and two studs holding the spring to the axle on the pass side.

Steve 72 4x4 · 05-01-2004, 12:45 AM

I agree with Mudder67, nothing higher than 4.11's. My 72 has 4.11's with a mild built 350 and it has all the power I need. No problem turning 36" tires. It will probably hurt your mileage quite a bit. I get about 7 - 8 MPG, although, that has a lot to do with the 3 speed automatic. It Runs about 2800 RPM at 55.

Budweis · 05-01-2004, 02:13 AM

depends on what you want to do with truck as far as gears, i currently have 4:56 gears with 33" wheels that sees some highway but i dont go over 65 , im changing to 35" tires so that should lower rpm a bit, i like low end power myself but if making a highway cruiser prob go with the 4:11 ratio sounds good.

IoWnZa · 05-01-2004, 02:21 AM

That link works well for figuring it out, thx BPB.

04-29-2004, 12:05 AM	#1
1971 2wd Registered User Join Date: Jan 2003 Location: PARADISE,CA Posts: 57	38" tires/gear ratio With 38" tall tires what gear ratio would work well?? Now I have 3.73 in 1/2 ton 72 blazer 4x4. Don't kown if I should jump into doing this swap?? Heres my deliema: Maybe getting 4.11 from 74 pick-up 4x4. The rear is 14 bolt and the front is DANA 60 flat top knuckle. Includes Drive lines, complete from hub to hub (front) and drum to drum (rear). He's calls it the heavy 3/4 ton. The big plus he said he install it all for $500.00! (axles & labor) Sorry if this seems to be a dumb A$$ question!! __________________ 72 blazer, 71 2wd short bed, 67 nova Too many damn toys!!

04-29-2004, 12:31 AM	#3
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	dana 60 front axle wasnt introduced in GM trucks til '77. as far as i know, all dana 60's have flat top knuckles...at least all kingpin dana 60's. it sounds like the front axle is actually a dana 44, which looks very similar to a dana 60. i'd be careful before i bought it. if you need to see pics of dana 44 vs dana 60, look in the link in my sig, and go to the photo album called "axles", you will find what you need there. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

04-29-2004, 04:40 AM	#4
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Yep I believe only dana44 are refered to as having flat tops and 1975 is in the range of years for them. Does it have 4 u-bolts holding the axle to both springs total or only 3 and 2 studs? __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

04-29-2004, 08:41 AM	#5
2wdBlazer The Blazer King Join Date: Sep 2000 Location: Valrico, Fl (Tampa) Posts: 1,213	I would jump on that 3/4 ton deal. I am currently running 3:73's until I can afford a 4:56 swap. It is really underpowered. I would get a minimum 4:11 gear. __________________ 72 2wd Blazer. Its the superbichinest, megacoolinest, superflowinest.

04-29-2004, 09:29 AM	#6
1971 2wd Registered User Join Date: Jan 2003 Location: PARADISE,CA Posts: 57	I probably wrong on what I said about DANA 60. 1969 GMC: I looked at the pics and they don't look like those at all. They are flat top. JIMs70GMC: Yes there are 4 u-bolts holding the axles. Are you talking about the studs on the knuckle? If so there 3. Oh I forgot to mention the guy also said they are the big wheel bearing HUB/ALXES. Did they make 3/4 ton alxes that were DANA 44?? I wish my camera wasn't broken I would post some pics. Thanks alot. Anymore? Keep them coming!! __________________ 72 blazer, 71 2wd short bed, 67 nova Too many damn toys!!

04-29-2004, 12:23 AM	#2
The Dude Registered User Join Date: Jan 2004 Location: glendale/tucson Posts: 199	get the new axles. more strength, and $500 is than buying 2 new sets of gears plus install.

04-29-2004, 09:30 AM	#7
Mudder Registered User Join Date: Feb 2001 Location: East Central, MO Posts: 11,336	Yep you'll need at least 4.11's. That sounds like the heavy D44 with the big hubs. It fools a lot of guys. Still a good set of axles.

04-29-2004, 09:39 AM	#8
1971 2wd Registered User Join Date: Jan 2003 Location: PARADISE,CA Posts: 57	Yeah, by looking at the front axle tub it look the same size of a 1/2 ton. I thinking 4.11's will fine with a well built 350 or a 383 stoker. __________________ 72 blazer, 71 2wd short bed, 67 nova Too many damn toys!!

04-29-2004, 01:52 PM	#9
BPB Registered User Join Date: May 2003 Location: East Coast Posts: 21	Here ya go. Check out this out

04-29-2004, 08:11 PM	#10
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	On a dana60 there's one u-bolt and two studs holding the spring to the axle on the pass side. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

05-01-2004, 12:45 AM	#11
Steve 72 4x4 Registered User Join Date: Apr 2004 Location: Iowa Posts: 10	I agree with Mudder67, nothing higher than 4.11's. My 72 has 4.11's with a mild built 350 and it has all the power I need. No problem turning 36" tires. It will probably hurt your mileage quite a bit. I get about 7 - 8 MPG, although, that has a lot to do with the 3 speed automatic. It Runs about 2800 RPM at 55. __________________ The Heartbeat of America... Yesterdays Chevrolet

05-01-2004, 02:13 AM	#12
Budweis Geared for Collision Join Date: Jan 2004 Location: St. Louis, Mo. Posts: 683	depends on what you want to do with truck as far as gears, i currently have 4:56 gears with 33" wheels that sees some highway but i dont go over 65 , im changing to 35" tires so that should lower rpm a bit, i like low end power myself but if making a highway cruiser prob go with the 4:11 ratio sounds good. __________________ MEMBER OF THE 4 WHEEL DISK BRAKE CLUB 1970 C/K20 3/4 Ton 1996 Collectors Edition Corvette 1977 Corvette Coupe

05-01-2004, 02:21 AM	#13
IoWnZa Big Block Blazer Join Date: Sep 2003 Location: Ellsworth, ME. Posts: 509	That link works well for figuring it out, thx BPB. __________________ [1985 Chevrolet K5 Blazer][454BBC][TH400][NP241][Dana 44][GM 12 Bolt w/ Eaton LSD][Hedman HTC Hedders][Dual 2.5" Stainless Steel Exhaust][Hedman Turbo Muffler's][Dual Spal's 14" Electric Fan's][32x11.50R15 BF Goodrich All Terrain TA KO's on 15x8 Rallys]



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