3/4 ton to 1/2 ton swap questions

[chevroletrucks]

I have a 70' c20 with rear coil suspension, I'd like to make it a half ton soon. I also have a 1967 1/2 ton rolling frame to use parts off of, although it's still drum brakes I know I can easily convert that with a kit. My question ,I guess is has anyone on here done this and if so how did it turn out with an earlier suspension? Control arms, width of rear diff. upper and lower control arms swap directly over or do you use the old front crossmember? stuff like that, any input greatly appreciated!!!
Thanx
Joe