I need some advice on muffler sound. The issue I have is the car sounds great at idle and at cruise, great from about 3000 rpm to 5,500 rpm, but if I nail it at low revs the exhaust sounds really "farty". It's a loud, "open" type noise, not a tight sound like at higher revs. The mufflers are a generic type from the local muffler shop, no brand. The engine is a 318 poly, bored to 328, 10:1 compression, fairly hot solid cam, 4 barrel intake, factory exhaust manifold, 2.5" pipe size I think, no H or X pipe, auto, 3.23 rear, standard converter. Any suggestions on mufflers that are reasonably quiet, but will give a nice tight note throughout the rev range, or is it more likely a result of the engine specs (cam etc)?