i had troyer tune my imp4 comp for my 4r70w, if i was you, being as you have the computer and harness already, check into the trans swap. check out built54's thread, JMC has done a sc'd 5.4 swap, and i have a build thread as well. check them out and weigh ur options

hey man sounds like you have a pretty bad ass truck i have a similar truck sitting on six inches with 315/75/16 goodyear mtr's i have a question for you what computer are you running in your truck right now did you use your stock computer and get it tuned or did you use the lightning computer the reason i am asking is because i have an 03 lightning engine sitting in my barn with the harness and the computer and i cant wait to get it in i am just trying to figure out which computer to use i have a 2001 with a 4.6 with the 4r70