Right now I run a straight pipe on my truck, but I need to put a muffler on it. Doesnt have to be functional, I just need to have one there for visual. I was gonna buy a Dynomax Ultra flow. Does it make any difference sound wise if it's an oval muffler or a round muffler? I dont think I've ever seen a round one on a truck, only ricers. The reason I ask is the round one is like $15 cheaper. If anyone can help it would be greatly appreciated.