shift Kit with 3600stall is it Bad comb?
You may also need to reset your shift points. Are you spinning at all? Spinning can mess up shifts too.
A shift kit like a transgo is fine to use. Just remeber that when you tune the tranny (e.g. don't crank up line presure and use a shift kit).
Have them raise your part throttle shift points too. 10% - 15% higher will feel a lot nicer around town with that big stall and cam.

