I am looking for the best combination of sound and performance from my 351 Cleveland. It is estimated to be about 375 hp and has FPA headers. I am toying with Magnaflow or Flowmaster. Also any thoughts on pipe size wiould be appreciated
As far as pipe size, you can't go wrong with a 2.5" setup, especially if its mandrel bent. As far as sound goes...you are on your own there, just depends on your own taste. I went on youtube and listened to a few guys setups. I went with an IMCO muffler that was a direct replacement for 2005 GT, so mine has that rumble without being obnoxiously loud, had flowmaster under my camaro and couldnt hear myself think, but it sure sounded mean...
Best advice for you is to go to cruise nights and listen to cars and ask them what their set up is, second to that is Youtube. Asking the flowmaster vs. magnaflow question is like asking holly or edelbrock, people either love or hate them.
I have had both, originally I ran flowmasters which I loved, great idle and they sounded mean, never seemed to loud to me, then switched to Magnaflows, they sound OK best at WOT, otherwise significantly quieter. I won't keep them to much longer, I want to switch to Corsa's.
I like Dynomax Ultraflo mufflers. I have them on my car now and think it sounds perfect. I had Flowmasters before and coudn't stand them. Anything but hollow tin can droning Flowmasters.
If you want a pretty loud exhaust, then get Race Bullets.
Straight through > chambered mufflers.
I also think that 2.5 inch piping is about right for your car.