sbronemann

2.25" all the way. Sounds great on a 5.4 with 18" long magnaflow tips. My old 03 would set car alarms off when cold and mellowed out quite a bit after warming up. It was still pretty loud and sounded great. I had 18" magnaflow slash cut tips on it as well. 2.5" IMO is too big for a 5.4. But that's just me. I might run 2.5" on my new 5.0. I will have to see what my exhaust guy says though. He has been doing custom pipes for 30 years out of his farm shop. He does great work!

7700SCREW

Never go smaller than 2.25" pipe on a v8. And yes there correct back pressure is a myth!

truckin97

Thank you for all the help and info it is greatly appreciated! When i finally get the exhaust finished ill have some picturesup unless we get snow before then

Carcrazygts2

stick with what ever the stock size is. I run 3" currently, but will be switching back to 2.5" once the new engine is installed.