I have a 2000 f150 4x4 with a 5.4L. I have noticed my factory muffler is leaking and would like to replace with an aftermarket muffler. I want the better performance but I am not too crazy on anything loud. So far it would seem I am best off with the flowmaster 50. I would like to hear from anyone with the 50 as well as get the part number I require. I will only be replacing the muffler.

 

I have the Flowmaster DeltaFlow 50 series on mine in place of the stock muffler. I had the shop weld all the slip joints on the system as they were leakin and the system was twisting.

The DF50 is not very loud, but is noticeably different than stock. I did not notice any performance changes, just sound.