As Sqidd has prof thats long tubes are the only way to go, Than I guess I have a special motor then because my 4.6 is by far stronger with these headers then it was before the install. I'm not here to argue about whats best. I'm only stating the fact that they work very well for me, my MPG went up 2 as well. I'm planning to go to horse power ranch next month for the numbers. Last night I laid to wastes a car that I could only stay even with last weekend. Could be the combination with the high flow cats I installed to, the flow rate is double what the stock ones are.
But again it could be just a freak thing too.
C&L Racer Intake. 87-91-93 octane programs from Brenspeed. Motion Plate Delete Plates(NOS ports). Throttle body spacer taken out 1 week after install. Ford Racing Shorty Headers, Custom High flow cats, Steeda UDP's. Steeda GT axel backs. Steeda Lower control arms, Shaftmasters aluminum driveshaft. A surprise rebuild by brother (Master Mechanic) He calls it a stroker. Custom heads and cams with who the hell knows what else.
Oh the NOS kit I dont have a bottle for.