I have a 2001 GMC sierra, 5.3 V8, 4-WD, SLT, extended cab, short bed truck. I want to make it sound more aggressive, but I'm only 16 so money is tight for me. I was going to get a cat-back exhaust system, but it's too expensive for me so I just decided to get a new muffler and I can't decide between a maganflow or a flowmaster.