Axle swap, 1970 GM 12 bolt to 1987 GM 10 bolt

[Big lou 915]

With working with what I have, I'm wondering if I can just bolt on my 1970's GM12 bolt to my 1987 GM 10 bolt both have the same gears.

Does anyone see any problems? I understand some mounts might need to be changed. Just let me know what you all think I'm going to attempt to take my old 10 bolt off tomorrow morning.

 

[roving4s]

I have no clue but my guess would be. Spring perches will have to be moved, and maybe some shock tabs.

 

[MrMarty51]

It will bolt right up, long as they are both square bodies. be sure they both have the same lug nut count, other wise You will need to pack two spares.
I dont know if the pre 73 diffs`ll innerchange.

 

[Big lou 915]

So a update to the project.

The two axles do interchange the leaf spring mounts were located in the same spot, I only had move the shock mounts to fit my truck.

The U-joint's are very different I ordered a 1310-1330 from 4 Wheel parts to fix my problem.

Just need to redo the rear brakes and get a new brake line.

 

[HotRodPC]

Good to know. So the spring perch spacing is the same. How about driveshaft length? I always wondered if 10 bolt and 12 bolt were the same pinion length and if you'd need to modify your driveshaft if you swapped from a Squarebody 12 bolt to a 10 bolt and vice versa.

 

[Big lou 915]

Haven't installed my drive shaft yet, I am barely getting my U joint today... From my mock up I don't believe i needed to change anything but I will keep you posted. I'll measure the pinions to see what the difference is.