1972 3/4 4x4 rear end questions

[jeffahart]

As long as you have to move the spring perches on the new axle pay attention to the angles. You can have the pinion angle dialed in on first pass. Don't just move the perches over without verifying the angeles. Plus my last 2cent tip is read all angle and distance yoke to yoke. Then reread angles after install. It's nice to have a baseline to work off of since you already got an assembly in the truck.

[Seventy468]

Originally Posted by Mike C

This is a recurring thread. Spring centers on 67-72 4x4 is 40.5", the same as a 73-87 one ton truck. 73-87 1/2 and 3/4 ton trucks have 42.5" spring centers, the same as 67-72 2x4 trucks.

So yes, you will have to move not only the shock mounts but the spring mounts. I preferred the 72 shock mounts on my Jimmy and used them on the '86 Suburban 9.5" 14 bolt that I swapped in. The SF 14 has 3 1/4" axle tubes so I reused the 86 spring pads.

I know the topic has been warn out thank you. I did a quick search and found mounds of threads asking "what will I have to do" type questions, which isn't what I was looking for. However you have provided me with great info, and that's appreciated. Thank you.

Originally Posted by jeffahart

As long as you have to move the spring perches on the new axle pay attention to the angles. You can have the pinion angle dialed in on first pass. Don't just move the perches over without verifying the angeles. Plus my last 2cent tip is read all angle and distance yoke to yoke. Then reread angles after install. It's nice to have a baseline to work off of since you already got an assembly in the truck.

Thanks for those tips, I'll keep an eye out and will eventually put together a "build" thread on this chassis resto.