just gettong back on line ....what gets me is you had the problem before and after new valve body install...other wise i would say valvebody culprit / and /or Servo...03 and up GM has already fixed valve body issues and improved on a lot of other things as well... I would still do the manual test with the brake to make sure its working like its supposed to....I dont have HP but have used Snap On DG and they are real acurate even list % of lock-up on all Sels... easy way to tell if youre tranny is worn out BTW,,,mine with 140k is still at 90% and is an 03 ...so yea man you got something going on ...I would re-check the valvebody flow make sure youre bearings where all put back ...did you do any drilling or opening...many things to look at ...its just not a cut and dry issue because what you have already done...if it was me and everything was done right i would look ito my pump flow...could be junked up and needs a rebuilt ...which you just do your existing one and clean it of course... that could be the culprit for sure...let us know what you find iam curios

 

attached is the log file from hp tuners, change Trans.txt to Trans.cfg if viewing using hp tuners. Pulled the pan yesterday to check the accumulator and check the clutch wear, everything looks fine. Also here are two screen shots of the log right after it shifted into 3rd at two different times. Currently i have the pressure in the tables almost maxed out to keep it from flaring.