Brad,in my 72 it has a 350 cu.in.it has a 2 1/2 inch dual system with Magnaflow mufflers.Best way I can describe them is they sound a lot like glasspack mufflers.If I keep my foot out of it they are just fine,however if I really get on it they rap pretty good.I personally like the sound of them.On my 55 with the 350 I have Flowmasters,they have a deeper sound,more of a roar.I dont have crossovers on either one.Flowmaster has about 2 or 3 grades of muffers,with I believe the 40s being the loudest,which is what I have.I dont know if Magnaflow has different sound levels on their mufflers or not.both are excellent performance mufflers.Oh yeah the 55 has a 2 1/4 inch system.good luck with whatever you choose. Dale
