Originally Posted by chevyz7120

i tested it on my 99 z71 wich has 3:73 gears and nothing made a difference except tow haul that slowed my time down in the 1/8th mile drag....manually shifting through gears helped me out a bit but your not always accurate

Originally Posted by kbracing96

With stock programing the truck will not shift into OD at WOT, so 3rd or drive makes no difference. I would also not run in tow/haul. It does have more line pressure for the shifts, but it also shifts at lower rpm when WOT then out of tow/haul.

Originally Posted by kbracing96

With stock programing the truck will not shift into OD at WOT, so 3rd or drive makes no difference. I would also not run in tow/haul. It does have more line pressure for the shifts, but it also shifts at lower rpm when WOT then out of tow/haul.

Originally Posted by kbracing96

Again, with stock programing and no shift kit, manually shifting will gain you nothing, because when it reaches the commanded shift point in the PCM, it will shift the truck whether you move the shift leaver or not.