Im considering putting x-pipes on my 99 SS. It already has a Borla cat back system which i love. Im also curious about cut outs. Any comments or suggestions would be apreciated.

 

First off, you would only be adding one x-pipe. Not "x-pipes"

Second off, you don't need dual exhaust if you have an aftermarket Borla system. The Borla system is more than efficient for your car.

Cutouts are nice if you get an electric one. If you keep your Borla system, you'll only need one cutout. If you go with duals, you'll need two of them. Electrics go for about $120 on SummitRacing.

I recommend a set of long tube headers if you don't already have them. That alone is good for 10hp.

If you really want dual exhaust, check out these thinks.

How-to install True Duals Exhaust | Tech Aids & Articles

LS1 F-Body True Dual Exhaust Systems

Those thinks should give you an idea of what you need to do a dual exhaust system.

Good luck and let us know if you have any other questions.