Actually, if you have a cat, a muffler shouldn't matter much. That'sspeaking for around here. Also, if i can remember right Thrush glasspacks have louveres or ribs in there that cancel out alot of high end. There is a mesh type that shouldn't cancel it out. Thats something to look up. Plus, they make glasspacks as short as 8 inches long. Shorter = louder. Cat-back systems are pretty much a step down from straights, especially with high flow cats. It's like the little brother of straights. Lastly, tips are mostly for looks but large tips cause the sound to echo, which bumps up the volume alittle.

 

Well I'm gonna just keep the single exhaust for now. Picked up a magnaflow hi flo cat on craigslist for 50 bucks. I just gotta cut a pipe for the single inlet cat. And I'm ordering a heartthrob 12 inch flowpack. $38 direct from them. Gonna wait til I get the
money and a set of headers to do the duals