this has been covered umpteen times.. i bet 2 minutes of searching and you woulda found 10 threads explaining it but, since im already typing....
Space your leaf springs out 1/4" on each side, with off set bushings, I used steel spacers on one side, and ground down the bushing on the other side. seems to work ok..
Hopefully you got the dodge spring plates from him, otherwise you need some of those.
You will need a new Yoke on the pinion... Order a chevy d60 pinon 1350 joint syle.
8 lug wheels are the same as chev, You might want to weld on some different shock mounts, The shock mounts on my dodge d60 are retarded and will soon be gone. Brakes work fine, i think... I had some stainless steel ones made, but if memory serves me i think they both work together (chev/dodge)
thats all that comes to mind right now... its been a few years since ive went through it.. All i can say is.. DONT SPREAD THE SPRINGS, to match the spring pads on the axle. itll flex and ride like Ass.