Hello.Hoping to find someone that can help me sort out my 4l80E. I've installed a 2007 Duramax into my 1991 pickup mated to a 4l80E. Is it possible to alter the shift tables so I can continue to use my stock TCM? It shifted fine with the 454 TBI but the Duramax peak torque is at different rpm's. PCM is 16147060. Thanks