Rear End Swap

[76C10Stepside]

My '76 C10 has a 12-bolt non-posi rear end Have not had it apart to check tolerances, but it has seen better days. This truck has wide performance radials on all four corners, but still gets terrible traction when unloaded. It loses traction very easily on wet roads, and the rear brakes lock up very easily. I just drive it normally, no drag racing for me. The left brake has a history of auto-tightening on its own, and the drums are at their limits (probably why the brakes tighten up). In contrast, my '89 S10 longbed with ABS and the optional sport suspension handles and stops awesome for a truck.

Am considering replacing the entire rear axle unit with a better one that has positraction and better brakes, if there is such a thing. Is there a later range of years that you can recommend getting a donor rear end from that I can do a direct swap into my C10?