Originally Posted by TMF Lindbeck
Then again cats and hi performance don't really go hand in hand.
Somebody should let the LS7 know about this so it can tone itself down a little.
To the OP, for a 350 or 383 you're not going to see a huge difference between 3" or 2.5" exhaust off the cats as long as it's quality mandrel-bent exhaust. There's many much bigger and meaner engines out there making due with a dual 2.5" system.