Will a 1995 Chevy Camaro z 28s rear end fit 1983 28?

No, a 1995 Chevy Camaro Z28 rear end will not directly fit a 1983 Camaro Z28. The chassis and suspension are significantly different between those generations. The axle width, mounting points, spring perches, and overall design are incompatible. You'd need extensive modifications, likely beyond the scope of a typical home mechanic, to make it work.