Difference between 1/2 and 3/4 ton 1968?

[.030over]

Ok guys, My first visit to this forum! I have been looking for a 67-72 truck for a good while and recently found a '68 C20 for a great deal. I am really not sure what I want to do to it but for a start I want to try to evaluate what I have. I hadn't considered a 3/4 ton truck to build until I saw this one that looks very much like the 1/2 ton trucks. Can anyone help me out with just what exactly is different between the C10 and C20 trucks. Is the frame taller or thicker? It appears that the trailing arms are the same??? How about the control arms other than ball joints? My first thought was that I was going to scrap the frame and do a nova subframe and a 2x3 box rear frame with 4 link. Now I'm wondering if I should just salvage some part of the OE frame and just shorten it to shortbed size and convert the front to 5 lug 1/2 ton stuff. I have a healthy big block and a 9" ford with rear discs waiting for it. I have done several chassis cars and trucks so I'm not afraid to dive in big with this one so give me your thoughts!
Thanks,
Scott