Edit is $550 and you need a laptop to use it. Jayson will help you out with your program. Just call him. But as far as tunning, a slightly modified 5.3 block with a mild cam used for towing, you could prbably get by with a Predator. Are you gonna tow the Vette with it? (Great flyby on that truck the other night in Galveston BTW) You could go as much as a 3000 stall and retain your stock towing capacity. Hey, if you don't like it, you caould always sell it. Here is my suggestion: mild cam 213ish 514ish, the LS6 heads you mentioned, but stock compression and 918 springs min, 2600-3000 stall. If your gonna tow a lot, you want your power to come a little lower in the RPM range. Getting to high with the cam is gonna kill you. I may be out at F&H Saturday with Toxic, we can talk more then if you come by.