You need to measure the difference between pad and center of prop shaft. If you have a gauge find out where 3 inches is and you can work from there. 2 3/4" to 2 1/2" to center is where most people run at WOT. The plate gives you the advantage of changing height of motor on the fly depending on water conditions. You don't need to go all the way down with the plate to take off. I usually don't adjust down except in rough water. Adjust your trim first then move the plate if you have too. Watch your water pressure when adjusting the plate up. After you run it alwhile you will get used to using it.