just remember the more angle pieces(especially 90's)you incorporate, the more power expect to loose!i wished i ran my car at the track last summer to see what loss it'd have with the bullets i made.like i said they were fairly quiet behind my 572.for anyone who doesnt know its hard to hush a big cube motor especially one without chambers!!!imagine a bullet muffler but with bigger diameter holes inside and more packing material.way way quieter than the jegs bullets(cheapies).my friend told me he made his mufflers so after listening to him about em he helped me with mine and i wouldnt ever trade em for a chambered muffler-oh by the way if anyone is running an old school evac system(tube from valve cover to header to pull out crackcase presure)it needs to be used only with a non-chambered muffler or no mufflers at all...like i said best of both worlds!!!