I added a set of long tube headers and an x-pipe; however, I did not like the sound of the x-pipe as I had in the past and switched to an off road h-pipe. I love the sound of the H-pipe. I thought the x-pipe sounded better with my Shorty tube headers, but I must admit "that different strokes for different folks. In addition, you must keep in mind that you will also need to look for headers based on whether or not you have an automatic or manual transmission. As far as the cams, you will also need to know what kind of transmission you have. This is critical when adding a cam as you may need a stall convertor if you have an automatic transmission. Nonetheless, you will need to assess what you want to spend and what will give you the biggest bang for your buck. I have a 98 Mustang GT with Mac Ceramic Coated headers with an off road h-pipe and side exhaust flowmasters. People love the sound and I love the torque.:bigthumbsup