I have a Thrush Glasspack on my 4.7L and it certainly isn't obnoxiously loud. It sounds quite nice and has a straight through design.

 

My Magnaflow has no drone at all, and thats dumped under the truck, YMMV. I also would like to know where the flow problems were observed, before my maggie was installed I looked through it, yep straight through it.

 

I think I had dragged on about the Flowmaster's "flow" (or lack thereof) in the part about Magna's. I know they have a straight through design, so my error on that. But I do not like the droning sound that both Flowmaster and Magna give off...which may be specific to certain models but I have yet to hear a model that sounds different. To my knowledge glasspacks sound alright for a little while, but crap out sooner than later....most that I've encountered made you want to stab your eardrums after hearing them, but I've yet to hear a cherrybomb. Ideally, a Gibson exhaust system would be great, but of course not all of us have a large bankroll to spend, so I'd say an Aero is the next step below if you just want to switch out the muffler and have a beautiful sound. Of course the disclaimer, experiences vary with everything. I say absolutely NO on the Flowmaster though, for clear reasons.

 

Aero Turbine mufflers also had my interest when I was trying to decide on what to put on my truck, but I could not find one locally the day I decided to replace my muffler. If its not too much trouble, could you take a vid or pics and sound clip of your setup?

 

If you want Flowmaster sound, you could use one of their Delta 40 race mufflers, like the 430408. 3in/out. About 576 scfm for airflow...

 

^That is true, however make sure you check what kind of warranty comes with it, and what it is made out of. Most Flowmasters rust quickly, and come with a 1 yr warranty I believe, which is a joke. Go stainless steel and save money and troubles down the road. Plus, their race line of mufflers are not street legal (as are many things, I know), but also check how much sound it produces, you don't want any unwanted attention.

BigDaddyII, I can definitely do that. Let me see what kind of setup I can get going to get the best sound quality. Also, those particular mufflers are typically not sold in your common muffler shop or offroad shops like 4wheelparts or others. I ordered mine from Michigan from a Diesel supply store, but it shipped QUICK. Also had it on sale, so I got it for a steal. Well worth the money though.