Lack Of Power

How many miles are on this engine? Stock 170s are not known for their necksnapping torque, especially not in cars heavier than the original '60-'62 A-bodies and with taller rear axles and bigger tires. You don't mention what kind of car this is in.

Inability to rev beyond 2800(ish) RPM suggests possible exhaust restriction. Do you own (can you get hold of) a vacuum gauge?

Have you checked for timing chain slack? See here.

Of course, don't forget the basics; Tune-up parts and technique suggestions in this thread, and you'll want to make sure to keep on top of the valve adjustment.