We have a 2001 Formula 330SS with 496's. It runs strong up to 48 mph but seems that if you try to push it past that it starts to cavitate and drops to about 46 mph, even though the RPM's go up. I've heard that when setup correctly the 330 with 496 should be able to hit low 50's pretty easily and at 48 it seems there is more to go. Currently running 28P props on the Bravo 3 drives. Any suggestions.

It should run way better than that. I had a 350SS with 496 HOs that ran 60. It also had B3s. You should be able to hit 60, or close to it with your set up. The 350 did not like much trim. Basically just a tap or 2 off fully tucked drives is where it liked to run. Otherwise it would porpoise and waste rpm.

Agree, over-trimming. Next time it happens start bumping the trim down and you should see the speed go up.

tabs all the up and keep bumping the drives up till it starts then bring them back down till it stops.

Agree with the others. The 330SS likes to run with a fair amount of trim 'IN', so you won't be able to trim 'UP' like many other boats.

The 496's should take you well into the mid 50 mph range.