Ok, just a "tad" over your budget, but I've used these before and have them on both Dusters now. They flow good enough, don't annoy the cops/neighbors, and don't really drone in the cab. these are normally about 48 bucks apiece, but this site sells them for 25 each. My 2 cents Dynomax Super Turbo Muffler 17733, Offset 2.5 IN / Center 2.5 Out 86387177337 | eBay
