3/4 ton Vs. 1/2 ton

[townzenm]

I'm new to this body style and was wondering what are the main differences between the 1/2 ton and 3/4 ton? Is the body all the same and just different suspension and possibly frame? I have been trying to find a decent project truck and I talked to a guy that may have one and he said it is a 3/4 ton with a flat bed. If it is in pretty good shape i figured I could just pull off the flat bed and put a fleetside bed on it. I plan to bag the truck so am I barking up the wrong tree with this particular truck?