Got the Superior Transmission super servo set, both 2nd gear and 4th gear apply with the cover. It was the best $110 part I've installed, took the laptop to it and turned the pressures down at part throttle so that 1-2 doesn't slam around town. But on WOT the belt screeches and the tires chirp on the 1-2 then the belt screeches again on the 2-3. Makes the vette servo look squishy. There is positive up and downshifting to all gears. Can't say enough good about it.