Does anyone know what diameter the stock exhaust tubing is for the 5.4??
I'm trying to decide what kind of exhaust system I want to put in. Its between using stock tubing with a flowmaster 40 or spend a lot more money on the magna flow 16612. I know a lot of people have and love the mag, but has anyone just swapped out mufflers?? If so, how did it perform? Any mileage gain? Oh and I'm not looking for the loudest thing out there, I just want my truck sound a little meaner and get some power and HOPEFULLY a little better mpg (I know, wishful thinking).

 

Factory pipe is 2.5". Check your local muffler shops. I had my SIDO Mag, mandrel bent pipe, 2 4x18 polished 304 SS tips installed for $300. A 14" or 18" Mag sounds like what you're looking for. I picked up almost 1.5 MPG with mine. I gained nothing with my Flows, other than drone.

 

from what ive read, maggy is the way to go, ill be getting an 18" mag si/do with custom bent pipe on my 2002, and the question he had, on my 2002 is the pip 2.5" as well?