I'm looking to replace my stock muffler, just the muffler on my 06 screw 5.4. I want it loud, but not obnoxious loud. Any opinions on if i should go with the 14 or 18. Not sure if the 14 will be too loud, or the 18 too quiet. Do i need an offset one or is center in cenetr out good? I'm also gonna get a ss tip, because the stock chrome tip sucks. Thanks

 

I put an 18" Magnaflow on my 01 with a 5.4. At idle it doesnt sound much louder than stock. During hard acceleration you can definitely hear it though. I did notice a bit of drone at approximately 50-60mph but it seems to diminish above 60. I would not call my muffler loud, perhaps noticeable is more appropriate. If you are looking for loud go with the 14".

 

Keep in mind that if you go with the 14", you'll probably get more of the constant drone similar to a FlowMaster. I'm happy with my 18" Maggies!

 

I took off an 18" and put on a 22" widebody. To much drone at 70-75

 

I had a 14" in my '05 Supercrew and loved it. There was no drone. At times I almost wished it was louder and I'm not even into extremely loud type systems.
I did have it mounted as far back as I could right before the bend to go over the axle, which would eliminate any drone due to being under the front of the box.
I also put on a 3" SS Magnaflow tip, which perfects the sound. Some pics in my gallery.