Have you made the mesurements on your tab indicator yet?? To show where your tabs are straght back from the hull. This basically extends the lenght of your boat, so to speak. Also, from what I've been told you shouldn't run the drive too far up and not all the way in either. Too far up and the gears are reaching and could chip...All the way in and you're mashing the gears= more wear on them. So I always run the drive(s) 'out a bit' and work with the tabs. Just my humble .02.
oh, and if you just super charge that thing you wont have to worry about running it so dry to get extra mph out of it!!!