Re: difference between stock, muff delete and 4" exuast
some folks say on lower hp trucks you get more low end torque with a 3.5" down pipe then with a 4". most of the restriction is in the muffler.
a few folks (nchornet and a few others)swear by the walker btm muffler saying it gives 80% of the performance of a 4" system.
you could always do the muffler delete 1st if not rpmoutlet.com has realy good deals on 4" systems , also some vendors like itp and di can get them cheap just cant advertise the price so give them a call as well.
Early 99 f350 4x4 crew cab, auto. pmt2 pcm
2001 cup holder ,T500, MAX AC ASSIST AC mod, Diy Twin tymar, TS chip, Powerslots & Hawk pads, ford AIC, ..... with big fat want to list.