Experience
I had a Flowtech afterburner muffler on my '95 F150 with a 5.0L and 3" single side exit exhaust. I loved the deep tone it had, but it wasn't as loud as I like so I gutted my cats. And as for glasspacks, I've never been a big fan. I don't see the point of them, just run straight pipes. Just my opinion.
Oh ya, I forgot one thing. A mustang magazine did a muffler test on the dyno with several big name mufflers and the Flowtech afterburner gained the most power and the 40's series Flowmaster was at the bottom of the list. I hope this helps. If you want more info on the dyno test I can try to find it.


