I'd like to know if TCC works now at normal speed. I take it no codes which is normal. TCC problems can take 100 miles before it sets a code. Mark mentioned stall was not right. bad sprag and race can cause a heat issue to unlock TCC. Could be a glitch in the lock box. I'm thinking.Agreed
Update-My wife helped me finish up the converter swap on this and I took the Q out of White Lightning and installed it in this truck and problem solved! Kills the truck when I flip the switch and stalls up like it is supposed too. Tweak a couple of other little things like the throttle pedal and be ready to go back to the track for another hit and see what happens now!