I have 2 street cars. One is a 360(9-1,224 hyd roller,LD340,650 holleyDP) 4 speed Challenger that runs Dyno-Max 2 1/2". Runs 12.50@110 thru the mufflers. The second car is a Volare with a blown 340 that runs Ultaflows. it runs 11.00@122 thru the mufflers. Both seem to do their intended job. The Challenger is fairly quiet,The Volare is NOT. I've never uncapped either one.
Doug