So my brand new, never used, Stage 4 4L80E is going in. Two companies sell the harness that makes it work with my 1998 PCM. Then they do the PCM internal changes for me. They said they need to change the shift points from my 4L60E shiftpoints to ones that work better with the 4L80E and its gear ratios.

So what shiftpoints are you guys using in your street cars?


Right now its just going behind my N/A 390ci...maybe 420 RWHP. When the turbo kit goes in I'll be upgrading to a 99+ PCM and will do the required tuning changes again.

.