2002 F150 Supercrew 4x4 4.6l factory 2.5in. in and 2.5in. out to tail pipe. Im going from the factory cat to 40 series Flowmaster 2.5 in and duals out. My question is should I keep with the 2.5 out on the duals or reduce to 2.24 in.? Im wanting to keep a deep rich sound but dont want to mess up my back pressure. Any help would be greatly appreciated.

 

nice...........

 

You could just swap the muffler and keep the rest stock. If you want the dual look are you going to use mandrel bent pipes or is a shop going to bend up the pieces? Mandrel 2 1/4 will be fine. Crush bent use 2 1 /2. What size comes in the Flowmaster kit? Dont worry about your back pressure. Between the cats and Flowmaster you'll be fine.

 

I'm ordering a kit off line to install myself. It comes with 2.24 or 2.25 out and both types of bends avalible but of course the mandrel bend being $40.00 more. I'm getting 3.5 in tips either way though.