Frame strength help...

[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.