I have a '06 GTO with a LS7 (427) Engine swap, originally equipped with exhaust cut-outs, 500+ HP....had them removed between the noise and exhaust in car, it was most annoying. A good Lingenfelter tuning module, catback exhaust and a few other minor mods and it outperforms the 50 or so HP you gain from no muffler.
I have a '06 GTO with a LS7 (427) Engine swap, originally equipped with exhaust cut-outs, 500+ HP....had them removed between the noise and exhaust in car, it was most annoying. A good Lingenfelter tuning module, catback exhaust and a few other minor mods and it outperforms the 50 or so HP you gain from no muffler.