I know that you have mentioned crusing speed....what speed are we talking here. I assume that it's happening either while in 3rd and 4th both at speeds where the TCC is commmanded to lock and unlock. Giving a little more infor may help us try and help diagnose the root of the cause.
And I was just saying mine is going to need a reabuild no matter what......Stock trans w/trans go shift kit only isn't going to last under a cammed turbo car![]()