Hi guys, I new at all this and need some advice. I have a 2001 HO,3500,QC,SLT,ETH/DEE, with 3:54 limited slip rear end , 4X4. I have 7500 miles on it, and am currently getting 17. 5 MPG without a load on the road usually running around 60-65 MPH (above 65 MPG starts dropping way down), and about 12-13MPG towing my 35' fifth wheel (about 12500 lbs. ). Truck is stock but I am thinking of adding pillar mounted boost and EGT gages, a complete Jardine 4" exhaust system, a K/N air filter, and a VA box. I don't have unlimited funds, nor do I want to jepordize my warranty. Am I going at this the right way? HELP!