I have been running just an 18" glasspack for the past year on my 88k5 and now its time to get it inspected. its to loud now it sounds like an old pulp wood truck. Where can i find a high performance catalyic converter that doesn't cost $130! 3" inlet and outlet. I m thinkn about runnin a flowmaster muffler what style or series would give the most power to my truck.