I have a 1987 G10 Sportvan with a short wheel base. The frame is rusted and rather than repair, I thought it may be worth investing the money in getting it converting it to a 4×4. Would be easier to repair frame then add 4×4 parts or can I simply put body of van on Chev truck chassy? I know the engine and tranny location of the van may be a concern? Is it doable? How?