I have a 2000 F150 4x4 with the 5.4L. To save a little $$ I would like to simply install a muffler only and reuse my factory pipes. I would expect that the most restrictive part of the sytem is the muffler, so I feel this would give me the most bang for the buck. Does any body see any problem with this?? What muffler should I use? Has anybody done this and what were the results? Thanks

 

I have a 4.6 and I just replaced the stock muffler with a Flowmaster Delta Flow 40 series muffler. I kept the stock 2.5 inch pipes. The sound is awesome, as far as performance, there may be a little more throttle response on the top end, haven't noticed much low end torque loss, but I haven't towed yet. I know it sounds faster anyways!

 

I just replaced the muffler to save $$ also. Guy at muffler shop said all the gains come from the muffler and if I wanted to for looks (no gain) could go duals out the back later. Noticed a difference, I think it is well worth it. Went w/ Magnaflow muffler.

 

A stright through designed muffler will provide more power at both high and low engine speeds. Flowmaster isn't known for performance, just sound.