Which conversion is better?

[moodybo]

I have got two trucks a 72 lwb(parts) and a 68 lwb. I am fixin up the 68. I want to use the disc brake setup and five lug. I have not decided if i want to just put my cab on the 72 frame or just swap out the front end and rear on the 68 for the 72? I also have a a front cross member complete with whole steering and rear to match from a 73 van! I beleive the van's setup is the heavy duty style. I know i have enough to build two frame setups which one is going to be better? the 72 style or the 73? Whatever i have left i will restore to swb and sell!

What kind of gear would have been in that van rear? I know it was an automatic!