HI everyone, I have a 1998 ram 1500 sport with the 5.9 v8 and I am looking to put on a whole new exhaust system. I am looking at headers a new y pipe as well as hi flow cats and a new muffler. what performance gains should I expect as well as mpg, what am I looking at as far as price is concerned and what are the best brands with the highest quality materials??? any input would be appreciated!!!!!