Hi,
I have a EL Fairmont 5.0 auto, 3.45 diff gears, K&N Panel, hurricane headers, factory twin cats, factory y piece, factory 2.5 inch system but mufflers have been replaced with hooker aero chamber and hotdog resonator.
Would any sort of cat back system perform better than my current setup. Engine is stock. Im looking for a few extra horsepower but not so concerned about sound. If my exhaust flows well, would another exhaust make any difference??