I have on my stroker 65 dart 402 magnum 3" x-pipe and dynomax ultra flo mufflers . fenderwell 1 7/8 " hedmann headers .They dump before the rear end with turn downs .
had flow masters 3 chambers on before this.
Unbelieveable hp gain !!! ultra flos flow 3 times as much as the flow masters . And it is quieter !!! I now believe the one tenth 1/4 mile gain !!
darty