Unlike 98% of the folks here, I too, want a QUIET muscle car.Talk to the folks at Dynomax, I ran the 3" long case Hemi reverse flow(17769, I think)on my car and they were fairly quiet, the engineer I talked to said they only gave up 5 horses to their ultra-flows which are considerably louder. I would talk to Accurate also, I know I will next time. Nothing like staging quietly next to a loud car and stompin a mudhole in 'em. Lee.