I'm looking at putting a new muffler on my 98 F-150 5.4L. Everything's stock. I just want something that has a good, deep rumble outside without a lot of interior resonance. Suggestions?

 

If you want to go with a Flowmaster I would recommend a FM50SUV or FM50HD. These mufflers have a larger capacity than the delta flow 40s and 50s and will help cut out the drone. I really like Dynomax Ultra-Flo mufflers, they flow like crazy. A turbo muffler would also produce a sound similar to what your looking for.

 

Go with the 50 series. =)

 

DKF, I've listened to some sound clips of both the Ultra Flo and Super Turbo. The UF seems to be just a tad louder than the ST. How's the interior noise on the UF?

 

When I had the ultra flo on my SD I had a lightning style exhaust with the pipes exiting in front of the right rear wheel. It was loud, but interior noise was not bad considering the circumstances. If you are really worried about interior noise, exit the exhaust out the rear of the truck. I think you would be pleased with an ultra-flo when exited out the rear of the truck.

 

I'm leaning toward the Dynomax Super Turbo, SIDO exiting behind the rear wheels. Thanks for the input.

 

I don't like the dynomax. I have heard it on a couple different trucks and you can barely hear it outside the truck.

A friend of mine had one dumped under the bed and had magnaflow cats. His truck was way too quiet like that. He went with a cherry bomb extreme. The cherry bomb elite may be to your liking.

I would go with the 50 series Flowmaster.

 

I have since changed my mind. I'm trying to decide between the FM Super 40 or the Thrush welded. I heard a 5.4L with a Super 40 the other day, and it sounded really good. I've also heard the Thrush welded muffler and it sounds good too. They sound very similar. I don't know if the FM is worth the extra $ if I'm just going for sound.

 

given the choice between the 2 and your descrption, definetly 50 series.

 

Flowmaster mufflers are constructed very well. I have no experience with the thrush mufflers, but quite a bit with flowmasters. If you like the sound of the 40 series go for it, it will just have more interior sound than the 50 series.