I have a 72 c20 with a new 330 hp 350 ci crate motor. Holley 600 700r4 and I have a Dana 60 with 4.10 gears. How hard would it be to get a rear end from a newer 2500HD to bolt up to the frame and be able to have rear disk brakes ? Or should I just keep the one I got ? I use the truck mostly for work. I do tile work and general construction so I do carry alot of weight usually. Would 3.73 gears be better or worse ? Thanks !!!