I had a 40 delta on my Ford Taurus, which made it sound really good. I've been searching for dyno charts on mufflers, and finally found one last night. Interesting, there really isn't THAT much hp difference between several makes...
http://www.v6z24.com/howto/mufflerchoice?*
Since my 4.7 doesn't spin to 6grand, I'm not to worried about those top numbers.
The Flowmaster 3.5" 40 series flows about as much as a 4.7L engine does at full chat, and I was really thinking about squeezing the pipe ends down and welding one of those in my truck...

 

I've got a Cherry Bomb Extreme, SI/DO on my truck and LOVE it. $54 online, great muffler. I had a FM Super 44 before that, awesome sound, but makes a godawful drone at highway speeds, which is a common complaint about any FM muffler.

 

Look under the rear bumper....there's a class III hitch there just no receiver for it. The receiver from dodge is like $90 and it bolts right up making it a class IV hitch.

 

welcome and here is how i did my aftermarket stereo to look clean with those cut outs!

 

@davb673
Thanks for that link. Thats a pretty handy sheet actually. It was quite interesting reading the results.

@pyro
Isn't it true w/ a si/do exhaust you loose back pressure thus resulting in a loss of power?

@SeVeReDiStOrTiOn
Thanks a lot! I just glanced under the truck and only saw the spare tire and was bummed. But taking a second look saw the hitch like you said, it just didn't have a receiver. Suppose I should contact the dealership for one, or do you recommend somewhere online?

@sharkhunter10
Thats a slick setup. I'm assuming most audio installers have those enclosures, or should I order it online, and if so, where? Btw, what deck is that :P ?

 

ya I just got it from my local setreo dealer and the model is a
Pioneer DEH-P6000UB

 

I think you'll find it is best to fire your subs upward because of how the area under your back seat is made,I also think you'll be happier with 10's for your kind of music.