I just ordered the last of the existing phase-out muffler that is as close as possible to stock dimensions. My plan is to get rid of the cats for high flow and run an x-pipe. This muffler proved to be extremely quiet, yet high flowing on a friend's 9 sec Mustang with turn-downs. Even with a lumpy solid roller cam, you could stand outside the car at the rear and talk without raising your voice.

That's definitely good enough for the truck. Anybody try these?

 

Nobody?

Everybody uses the aftermarket pre-fab exhaust kits only?