Best Prop for my '74 20'CC

[Ulf]

New Seacraft owner, '74 20'cc with a Merc 150 Blackmax.

Finally installed the GPS unit, topping out at 43/44 mph @ 5400 RPM. One person, light load, 1/2 fuel?

Does this sound right to you guys?

Running a stock Merc 14x19 s/s dog ear wheel.

Could I get more MPH with a different style prop?

Also think I can go up at least a bolt hole on the transom. My cavitation plate is below transom at nuetral/ negative trim. How are other boats set up with engine height ?

Just looking to make it as efficient as possible.

Thanks Guys