is this right ?

[88 regal 3.slow]

hello everyone im new to this forum figured id join up today... i currently have a 1988 19ft regal cuddy with a 3.0 mercruiser... i just replaced my prop and i put a 14.50 X 17...... the prop that came on the boat when i bought it was a 14.25x17... at WOT i am only turning 3950-4000 rpms!!!??? should i be turning more? i know the max for the engine is around 4600 i believe... the boat a REALLY slow!!! any suggestions on what size and pitch prop i shoiuld be using???? thanks in advance...