New 1970 c20 owner with couple questions

[noskiki6]

I bought a 1970 C20 with utility bed. My plan is to make it into a short bed 2wd 8 lug. Green a white paint. My mechanic is going to take it apart for me so I can paint the firewall and the inner fenders. Maybe green firewall and white inner fenders not sure. Last Friday I bought a Silverado to used the engine and transmission for my C20 but I have a question, has anybody used the A/C from a 1999 to 2008 on their C20 Or C10. Do you guys have pictures? For me is too much 900 to vintage air. I bought the entire truck why not use the A/C.