60-66 body on 67-72 frame

[c20pickup]

hey guys been wondering what would all b involved in swapping a 60-66 body style chevy or gmc onto a 67-72 k10/20 frame. just one of those things ive been wondering about, the 60-66 4x4's seem to be few and far between and if one could get ahold of a 67-72 4x4 frame what wuld be involved in swapping bodies over. i read somewhere that a 60-66 frame is narrower, any truth to this? what about even swapping onto a 73-87 frame.