Will 1995 Chevy 1500 4x4 5 speed fit in 1986 4x4?

No, a 1995 Chevy 1500 4x4 5-speed will not fit in a 1986 Chevy 4x4 chassis without significant modifications, likely more than just a simple swap. The body styles, frame dimensions, and drivetrain components are substantially different between those model years. Even if you could somehow make the engine and transmission fit, the mounts, wiring harnesses, computer systems, and other aspects would be vastly incompatible. It's a project of enormous scope, not a simple swap.