After installing my Power Puck I could make the truck shutter shifting into third with heavy pedal pulling my 8,000 lb boat. Pulled this weekend after installing DTT Valve Body, what a difference. This is how it should shift from the factory. During my first test drive I thought the truck shifted into overdrive right after shifting into 3 gear, it was going into lockup. I never felt lockup actually happen firmly while stock. Shifting while towing is great, firm shifts no matter how much pedal I now use. I installed the adjustable voltage regulator and that sure made adjusting the voltage simple, set at 4. 8 volts and shifts great. Thanks DTT!!!