I always hear on here that mufflers and the right size exhaust tubing will make more power than say gigantic open pipes. I never bought it and ran tubular manifolds/shorty headers with 2 1/4" pipe and cherry bombs that dumped down right after the cab. I replaced the cherry bombs with Dynomax Super Turbo Muffs and the mileage went up and hand more power. Today I had a complete professional setup bent that exit out behind the wheels, all with the same muffs. Now it has a heck of a lot more power in every part of the band and when the secondaries hit on the higway, it'll throw you back in the seat. What is the physics behind a system that has more restriction in it (mufflers) and more pipe to go through. Does it have to do with making more cylinder pressure, or what?