Strangely enough, I actually want a quieter exhaust. I currently have a pair of generic IMCO mufflers and only 2-1/4" pipes. I want to go to 2-1/2" pipes, with a crossover, and possibly a larger(quieter) muffler mounted parallel to the rear axle as per stock type set up...or a combo of some sort.

I heard a GTO that sounded great at a cruise last month. He said he ran Flowmaster 3 chamber mufflers.

Any suggestions?

I ran 3" Flowmaster mufflers on a 400 and it was way too loud at cruise but sounded great at idle. The drone that comes at speed with the flow masters is a headache to go if you have to travel very far. I saw a FB recently at the dragstrip run a 11 flat 1/4 mile with 2.25" factory style pipes and a cross flow type muffler in the stock location. It makes me rethink running super load pipes for performance.

My car had Flowmaster 40 series on when I bought it. The noise that came out of them was horrible. Noise, not a deep, throaty, powerfull sound, just loud noise. My wife didn't want to ride in the car as she thought It seemed like we were just trying to get attention with the loud mufflers.
I asked around and everyone had a different opinion. Then I read Jim Hand's book. He did extensive testing with quite a few mufflers. Decibels at different rpm, back pressure at different rpm, and how they performed on the drag strip. He compared them all to open headers. Man that guy's dedicated.
The results were surprizing. Some of the loudest mufflers only flowed just over half of the open headers and some of the quiet ones flowed nearly as well as the open headers. As the exhaust system was already made up for 14" mufflers I chose 14" Magnaflow. They flow well and are a great deal quieter than the Flowmasters. Not only quieter but they just sound better. My FB buddy put DynoMax Ultra Flow on his and they sound great and not as loud as his old ones were.
You almost need a bunch of mufflers with a quick connect system, so you could test drive them all.
Hope that helps some.

I'm interested in a test on the cross flow mufflers that install in the factory position. I see there are at least 3 brands now. On a past 68 Camaro, I had clearance issues with mufflers under the back seat area under the car. They cleared fine but we're always the first thing to drag over speed bumps and dips.

From that same Jim Hand book, I have the Goerlich Xcellerator's which flowed 99% or something like that. They have a nice healthy sound at idle and not very loud, but when you hard accelerate they growl nicely.

At cruising speed they didn't reverberate and buzz your ears to death. I like them and would recommend them.

I am probably not the person to provide a suggestion here. I put Pypes Violators on my car because the description said "for those who want to be noticed".