I used one hole and installed all the springs included with the kit,,,,,But I still did not think it was good enough so I bought and Suncoast Modified Valvebody w/ shift kit and installed it. I am still not personally satisfied with the trans shifting. I think it's more do to the 48RE being a crappy trans and needing to keep the bands adjusted on a regular basis. It does shift strong and chirps the tries under moderate acceleration and light acceleration will break them loose on wet roads without trying..Wot is hard and will sometimes chirp them going into 3rd especially from a roll and hitting the tow/haul button.....The hardest part was getting the kick down shift points to where they felt the best during light and part throttle....All in all much better than stock...