i am planing on doing a down pipe upgrade to my truck. I am looking to put in a 3in downpipe in. I have been looking at the different makers out there and I was just wondering what every one else is using. also I was wondering if anyone could tell me what the difference in say mbrp, bully dog, flowmaster, and bd diesel's down pipes. I mean other then mbrp all the other pipes run over 100$$ and as far as I can tell they are all pretty much the same.