Frame strength help...

[57taskforce]

Originally Posted by stubs

Dont know if this helps but 67-72 c20 frames are actually stronger then their k20 conunter parts. The gvw of a k20 is way less and also the fact I've looked into a k20 of this era is basically a k10 with stiffer springs and axel. Also some c20s came with Ho72 to handle the higher gvw. Know I dont know if there is any specific bracing that a 4x4 has but I would say a c20 will be fine. A c10 might be another issue.

This is exactly the truth, longbed K trucks in 67-72 used the same identical frame. I’d imagine the 60-66 trucks are similar. Spring and axles were the difference between 1/2 and 3/4. 1/2 short and blazer used thinner gauge frames, suburban used a variation of the longbed frame.

It’s the same in the square body years for the 1/2 and 3/4 trucks, the K30 frame in the sqaure years is 100% different and 100% beef lol.

I doubt this post is still relevant to the OP but I would have used the original frame and not thought twice.