is the intake manifold and heads from a 1995 chevy s-10 4.3 blazer compatible with a 2001 chevy s-10 4.3 pickup

Doubt it, different electronic controls must coincide with the pcm, and wiring configuration

it will bolt up but the 2001 heads and intake are far superior to them. The main difference that will make it not work is the fuel injectors are completly different and wont work with your ecu and arness. What made the 95 have a little more power was the cam and tune. Get a mild cam and a custom tune for the cam to take advantage of the power.