Ok I guess I'm officially an old fart now because my American Thunder cat back is just driving me nuts. I want something that's quieter at idle and has no constant drone while cruising. I don't care if it's loud at WOT. I'm planning on keeping the 3" Ipipe and over axle pipe and just changing mufflers. I did a search and found alot of people liked the 3" in dual 2.5" out ultra flow pn17227 with stock looking exhaust pipes. I am considering this muffler. On the Dynomax website I found a 3" in dual 3" out muffler with stainless tips that is for 98-02 camaro/firebirds. Is anyone using this muffler on their cars? It's pn 17536. Thanks.

Not exactly what you are looking for but here goes. I had the Mufflex 3.5" catback installed on my car. I installed the Hooker AeroChamber 3.5" Muffler with it and it was to loud for my tastes. Probably just right for most. Hehehehe.

Magnaflow finally made their 3.5" muffler with the single inlet and outlet. I installed this muffler and what a difference. It is on the quiet side and is of the straight through design so has plenty of flow for performance. I can guarantee there are no exhaust restrictions with this setup.

I can cruise down the street with the window down and hardly hear the exhaust. I would imagine that the Dynomax muffler would be similiar as it is of the same design. Being as you will be buying a 3" muffler it should be a little quieter. All in all I'm very happy with the Magnaflow muffler.

I haven't used a dynomax either, but regarding quiet mufflers...

have heard and driven in an 88 IROC with a borla Pro XS (P/N 40474) muffler. nice and quiet as stock, but still great flowing.
http://www.borla.com/proxs/pages/muflrtrans.php

I have an SLP "dual dual" muffler on my 91. The "dual dual" muffler was an option on 4th gen SS cars. Also nice and quiet and great flowing, as verified by many LS1 dyno runs. Most LS1 guys consider the only valid reason to replace it is to get something louder if you're so inclined.

Would recommend both if you want free flowing (non baffled / non chambered) mufflers that are truely quiet as stock.

Thanks for the response guys. The borla muffler looked pretty good. I checked out the SLP website but didn't see the muffler you were talking about, just the 2otl muffler. Do you have a part # for it? Besides being quiet I was looking at the dynomax because it looked reasonably priced. Are the SLP and Borla mufflers expensive?

Thanks.

You should look for some RAVEN sound clips, I've had that in my car for sometime now, and I still love the sound. It's more of a low, deep rumble sound

I got the Borla 40474 on ebay about a year ago, someone was selling them now for about $100 or $110 I think. They were up there pretty often. I don't know if they are anymore, but a Borla dealer might be / should be able to get it for you either way.

As for the SLP, I got it off ebay too, but I got it used. They sell new for close to $300 (yes, just the muffer alone) but the design just doesn't wear out or get old so when a clean used one came up I bought it.

Someone has them on ebay new right now for $160, see ebay number 7992998291.

Pricy, but if you want quiet as stock at both idle and WOT, while still free flowing, these two are one of the few that do it.

im useing a dynomax or dynoflow (somthing dyno) muff (or rather it came on the car) its so silent, when i first jacked it up i was vary saprized it wasent oem.....i want to get rid of it for somthing louder, my .02 if its going to be a moded v8 it should sound the part

are you interested in getting rid of your flowmaster muffler? LMK thanks