I have a 04 with am lm7 with 155k miles and a rebuilt 4l60e (rebuilt 1k miles ago). I want more power for acceleration. I am thinking about getting a cam and headers but I am fairly new to the performance world and I don't know what supporting mods I will need if I get a cam. This is a daily driver but I wouldn't mind a big cam as long as it wont cause a lot of problems. The 2 headers I am deciding between are Doug Thorley or OBX and I will probably run true dual straight pipes out the back. The cams I am looking at are all Comp Cams they are XFI? Xtreme Truck, G3 XFI 260 HR15, XFI? RPM, XR265HR, or XFI? RPM, XR269HR. Some of the cams say they need a programmer, do I need to buy a programmer to go with the cam or can I just have the truck tuned by a performance shop and if I need it tuned how much will that cost? Also will I need new push rods, rocker arms, springs, or anything like that? Any tips on what to get and do are greatly appreciated.