I have a 1955 GMC 150 3/4 ton longbed truck that I bought this past year. I am going to convert it over to a short bed and use a mid-seventies firebird subframe that I already have. I haven't decided on the rear end or rear suspension yet. I have seen how people shorten the frames for the shortbed and it doesn't look that complicated, but was wondering if i would be better off just finding a shortbed frame to put my subframe on? Most of the suspension stuff I've seen for the rears say 1/2 ton only. What are the real differences between 1/2 ton and 3/4 ton chassis?