I have a 04 rcsb 5.3 an I just took it to the track for my first time last week an I bairlly stalled my truck up to 1200RPMs tops, an the best I could run was 14.89@93MPH. I dont know why I didnt do it, but I should of stalled it up way higher cause my rear tires never spun once, I guess I was just nervous on the line a didnt pay attention. I will fix that next time. . But when I am just playing around on the crappy streets I can stall/launch at at least 1500RPMs or higher an still hook-up pritty good. So if you can only lunch at 1200 without spinning then you must have a problem with your tire pressure or the tires are not real slicks. BTW, I noticed you have a Nelson tune but do you have any other mods other than the G80 rearend, cause that is still a good time?