8 lug to 5 lug c20 to c10 Noob don't throw rocks LOL

[musicman75]

I've loved the 67-72 trucks for some time. So much that I have sold my 68 chevelle project and now jumping into a truck project. I just bought a 69 c20. I would like to eliminate the 8 lug wheels and go to 5 lug like the c10's. That being said, I don't know what years are interchangeable for this. I would like something that bolts in without breaking the bank. I have access to a 76 c10 parts truck....but I don't know if they share the same wheel base etc. I have the trailing arms/coil spring setup. So far I know I want to do the following:

4.8L /5.3L/6.0L engine/tranny transplant
4 6" drop

Please be gentle as this is all new to me.....if it was chevelle I could talk your ear off LOL. Any help would be appreciated. Thanks in advance