Swapping a 71 cab/front cap to a 68 frame, can it be done?

[LeftEar55]

I would like to know if I'll run into any problems swapping a 71 front cap and cab onto a 68 frame? I've been looking through some parts books from a guy at work and say for instance, the core support mounting kit says it's different on a 67-68, then a 71-72, is this true? Also, read somewhere that the doors on a 67-70 were the same and the 71-72 were different? They look the same to me? Well, those are my main questions at the moment? I guess I'm going to have to become a supporter, because I need some parts for this truck in the near future.