I would like to hear from anyone who has modified their throttle valve sleeve the way Pro Built suggests. How is the normal function of your transmission affected, for example, how are the detent down shifts between 2-1/ 3-2? How has your transmission held up ? Does it upshift at W.O.T. into fourth gear? I recently installed a Superior W.O.T. upshift sleeve and guess what, it does'nt work at all. So before I take another Dexron bath I thought I would ask the thirdgen community for the collective opinion.