I'm not familiar with that hall but I know it makes a difference whether it's a quarter string hull or a full stringer hull.
Your boat should be capable of 75 miles an hour quite easily as long as your hall does not have a hook in the bottom best way to check is a long straight edge on the bottom side of the hull. If it's straight there should be no gap anywhere along the straight edge.
Next would be to add Power to the engine and pump mods. Could be as easily as an impeller and tolerances of you to make it more efficient. One thing everyone will say and agree with I'm sure is speed comes with a price 💰💰💰


Twinturbo

It's got full stringers so that's good. And the money's getting thrown at as we speak:/

You should develop a build plan and a budget.  It is really easy to have grandiose dreams and start a build that never gets finished.

First, you should make the decision to either rebuild what you have now or to start fresh.  Next, decide what fuel you are going to run.

The pros of building what you have now is that you could save some money by reusing some of your existing parts.  The cons are that you risk rendering a perfectly good running engine into a pile of useless parts.  You may also spend more by ending up replacing everything anyway.

The pros of starting fresh:  you retain your currently good running engine and therefore can continue use of your boat.  You have a backup engine if you break your new engine.  The con is, you have to start from scratch.

As far as your engine build is concerned, remember the phrase, "cam, carb, and compression."  Cam; you will need about .100 lift per 100 horsepower.  Carb; this really relates to total airflow and not specifically to carb size.  Your heads and induction need to have flow capabilities to support your horsepower level while having a small enough cross-section area to maintain a high velocity of the airflow.  Compression; you need to add compression to support everything else.  More compression = increased efficiency and more power.  When a cam of increased duration or the same duration with delayed intake valve closure, dynamic compression ratio is lost.  An increase in static compression ratio is required to compensate.

Once you make more power, there are some minimum things that need to be done to make the pump survive.  An aluminum impeller will develop cracks.  Stainless will support a lot of power and can be repaired.  You will need a 17-4 stainless (magnetic) shaftn so you don't twist the splines, at the minimum.

Before doing a lot of bottom work or even diving into an engine build, bolt-on hardware can get you a long way toward your 75 MPH goal by simply improving the ride.

There is a lot more, but hopefully this will get you started.

Good luck,

Joe