Yep, mine tends to porpose at low speeds (30-40)...somewhat able to dampen with the PD but not totally. Possibly a setup or hull design issue...not sure that could be "cured" without sacrificing top speed. Not much room inside, and the tunnels keep the seats a little higher than I'd like. Certainly not a family boat or the best for camping. Freeboard, what freeboard? When waves kick up it's time to head for the cove and shut her down. In a turn tends to do the tunnel slip-hook-shuffle, some of which can be controlled with trim, but not really comfortable to me. Definitely a straight line runner.
So what do I think? Weeeelll. I absolutely love mine! Add hp and this hull moves. Trimed out and you get that floaty feeling. With a mild 454, I'm only turning a Berkeley B at 5k (on the engine) and that's good for 73 mph in lake trim...and about 75 mph with just driver/light load. This is just your basic 454 with low (9.5:1) compression and timing. Not bad for 340 hp on a jet? So I think your goal of 80 mph with a well-built Ford is certainly attainable. Shoot for 425 hp and you're in there. On the bottle (conservative jets) I get 82@5400 lake trim and 84 with just driver. The hp/mph curve shows very little drop-off at this speed, so the tunnel is just beginning to strut it's stuff. The hull is strong...can take just about any hp you can throw at it...as top fuelers have found. Finally, I've always liked a pointed bow on a tunnel, with an upsloped deck instead of a flat deck, but that's just my personal opinion.
jer