It's been along time since I've seen one that wat but I would say at least 4" maybe more.

hey Ryan, my 24, S3, Striking Distance, ran 104 with 2.5 Bridgeports and a blueprinted bottom. The engines were even with the bottom,ie points of the crescent were aimed at the bottom in neutral trim. I had a race hatch and recently sold it. Thing was about 60 lbs. The front was 4-5 inches below the gunnel. We found optimum height with a gps. The boat didn't like it too high up. Oh, and I never turned the props in. Couldn't keep it going straight in the sloppy stuff. Take care.

I Run mine turning IN. 14.5 / 30 choppers ,ears cut and extra cup-6 inches on detwiller plates. would reccomend having a tunnel tab made aswell. Good luck