[David Pozzi]

I have heard of people not liking rear bars or removing them and getting better results. But every car I've worked on needed one. In particular, first and second gen Camaros needed a pretty substantial rear bar if the front bar is a very stiff one like most vendors sell.

Lighter front weight will require more rear bar or less front.
Wider rear tires than front will require a heavier rear bar or less front.

A matched set of bars is better than a mix and match set. Even if bar sizes are the same between mfr's, the mounting may be different and affect actual bar rates at the wheels.
David