25 Eliminator 496 to whip 500 EFI

[HaxbySpeed]

I've got a customers 25 Eagle that started life with a 496 mag/bravo I. Now she's sportin a whippled 500 EFI with merlin heads, JE pistons, and Manley H beams. The drive is an XR with 2" speedy lower. We tried a 30p B1 but it was still accellerating when it hit the rev limiter at 5700rpm and 90-92mph. We tried lowering the drive and improved the slip numbers but the boat is less stable and still won't get past the 92mph mark.. I did a few other mods over the winter and we went for a quick sea trial yesterday and it's now on the limiter at about two thirds throttle. Should I jump up to a 34? Try a different style prop? Help..?