1959 chevy 3/4 ton

[cam210]

hi new to this site, i have my 59 chevy and i want to convert it to a 4x4 it has the i beam front axle and leave springs. i have a 80 k5 blazer im giong to for parts, it has 3/4 ton axles on it with a 6" lift. i know the frame is not long enough to put the body on, im trying to find out if a short bed frame would work for a new frame, or do i need a long bed frame? it is a long bed stepside. i have seen the short bed version of this truck and it looks like the only diff is by the tailgate. i know this is not going to be a weekend project but some in put wood be nice. thanks