check your bottom. you can spend all summer swapping props. some will be better than others, but the boat will never run right with an uneven bottom. get a long straight edge and check the bottom for hook or rocker. check the bottom on all strakes, not just the very bottom running surface. if your bottom is bad, fixing it will make your boat much better to drive, be faster and burn less fuel. good luck and i hope that you can get your boat running right.

how do i go oabout fixing a hook? or am i going to need to find a good fiberglass guy?

Depending on how deep it is you can either sand it out or fill it in. I'd find a glass guy unless you're good at it.

Griff,
Your 24 Bravo 1 stats are interesting. Our 454MAG with 460HP is at 5100RPMs at 68mph in a Checkmate 259 Convincor. I am not sure about the prop shaft distance from the bottom.
Rob

my first boat was a 24 ft baja outlaw with a 502,if my memory is correct i ran a 24 pitch 3 blade prop labed to 25.5 the boat ran 67 mph with little over half trim & had no porpiss as you say. it did chime side to side at top end though.