70 4x4 chevy pu axles vs 71 4x4 blazer axles - The 1947 - Present Chevrolet & GMC Truck Message Board Network

70Chevy4x4Nut · 03-04-2003, 04:40 AM

does anyone know if there were any differences between front and rear axles/housings used in 4x4 trucks vs those used in 4x4 blazers. Were some heavier than others. Both are 1/2 ton models.

I am restoring a 70 4x4 and I purchased a 71 4x4 blazer donor vehicle for parts. The blazer has front discs which I will use. I don't know whether I should replace the whole assembly or just remove the discs. One thing that might have a bearing on this is that the blazer has a detroit locker in the front. I would want to swap that out too. The gears on both vehicles are 3.08. And what about the rear? neither one seems to be posi in the back, yet I don't know if the axle housings are of the same construction. I have not compared the drum sizes yet. Want to check axles and see if maybe the blazer had any modifications done to the rear. Anything in particular I may look at?

Any knowledge on any of this?

Thanx again

BLAZIN'72 · 03-04-2003, 07:03 PM

As for the front i would just do the swap. It's heavier work but not as much, especially if you want that posi. As far as the rear goes chevy lists 2 different part numbers for 67-70 - 71-72 for rear drum shoes, so the drum size could be different between the two but the housing is the same. I would remove the rear diff cover of both and inspect the ring & pinion of each and roll with wich ever one looks fresher.

**JIMs70GMC** · 03-04-2003, 07:19 PM

Both rears should be chevy 12 bolts. For the front as was said just swap the whole front axle.

70Chevy4x4Nut · 03-04-2003, 10:58 PM

Thanks guys. I will use your suggestions.

03-04-2003, 04:40 AM	#1
70Chevy4x4Nut Registered User Join Date: Dec 2002 Location: TX Posts: 311	70 4x4 chevy pu axles vs 71 4x4 blazer axles does anyone know if there were any differences between front and rear axles/housings used in 4x4 trucks vs those used in 4x4 blazers. Were some heavier than others. Both are 1/2 ton models. I am restoring a 70 4x4 and I purchased a 71 4x4 blazer donor vehicle for parts. The blazer has front discs which I will use. I don't know whether I should replace the whole assembly or just remove the discs. One thing that might have a bearing on this is that the blazer has a detroit locker in the front. I would want to swap that out too. The gears on both vehicles are 3.08. And what about the rear? neither one seems to be posi in the back, yet I don't know if the axle housings are of the same construction. I have not compared the drum sizes yet. Want to check axles and see if maybe the blazer had any modifications done to the rear. Anything in particular I may look at? Any knowledge on any of this? Thanx again

03-04-2003, 07:19 PM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Both rears should be chevy 12 bolts. For the front as was said just swap the whole front axle. __________________ 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

03-04-2003, 07:03 PM	#2
BLAZIN'72 Active Member Join Date: Mar 2003 Location: Ontario,CA. Posts: 108	As for the front i would just do the swap. It's heavier work but not as much, especially if you want that posi. As far as the rear goes chevy lists 2 different part numbers for 67-70 - 71-72 for rear drum shoes, so the drum size could be different between the two but the housing is the same. I would remove the rear diff cover of both and inspect the ring & pinion of each and roll with wich ever one looks fresher.

03-04-2003, 10:58 PM	#4
70Chevy4x4Nut Registered User Join Date: Dec 2002 Location: TX Posts: 311	Thanks guys. I will use your suggestions.



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