The stock TCM programming is your nanny... It defuels on every shift. The Allison was beefed up for 2011... People are running 500 - 600hp no issues. If you go full potato when loaded to the nuts on a hot tune, you might have issues... But so far, I'm good, lol. I'd imagine for the '17s the upgraded the clutches and the torque converter.... Or at least the torque converter.