1993 Johnson Fast Strike - Loss of power

This engine has been fantastic as far as quick starting and well running. However, I cannot figure out why it is so slow.
The boat is a 1988 Procraft 1780V with a 5.5" jackplate.
The best prop I've tried so far is a 14.25D raker 22p.
Engine Model # j150GLETR

With this prop I turn 5,000 rpm with a top speed of 44mph. I have tried several props and jack plate heights. If anyone asks I will have to double check but I'm fairly positive my current prop to pad is around 4 inches. seems any higher than that I blow out when getting on plane and significantly lose handling and have no gain in speed.

A compression check with cold engine, spark plugs in, and not at WOT reveals all cylinders around 90 PSI. I understand that is a little low however I have read that several of these engines run great with similar compression.
I've pulled the heads and inspected the cylinder walls and found minor scoring but nothing significant. I have always used the VRO and mixed around 70:1 in the tank for a little reassurance.

It is possibly worth noting that while on plane water seems to start ejecting from the sides near the middle of the hull and not so much near the stern. I've noticed when trying to adjust trim to gain speed that I can only trim up a very small amount before losing speed. As far as hull condition i'll say it's an 88. it's seen a few bumps and has some gouges and scratches on the keel and hull but again, nothing significant.

I just believe this combination is easily capable of over 50mph and I cannot figure out where the issue is.

Any advice or suggestions are hugely appreciated.