A MAC Prochamber is a mid-pipe option &
will give a nice deep rumble. A Prochamber increases horsepower on any system it's installed onto. How much depends on the vehicle and other mods, ect.. already in place. LT headers and a Prochamber netted me 10HP. It sounds good. It flows great.
Here is some info to look at:
Patent US5740671 - Balance box exhaust accelerator - Google Patents