I/O Sterndrive Performance (Seacraft 23') Mercruiser 5.7

[Hooligan]

Gentlemen: I am looking for some numbers for the performance of my I/O with 5.7 Mercruiser sterndrive. Motor is Carbed Mercarb 2 barrel. Factory target WOT is 4200-4600.

Currently I am overpropped (new one on way) and am only turning 4000 RPM at WOT turning a 15 1/4x17 Black max prop. Leg is Alpha one gen II 1.47. New Prop is 15x15. Mercury claims 200 RPM drop per inch of pitch.

Boat now does 34.5 knots at WOT. Boat is light, has no top and no real gear onboard except safety gear. What kind of numbers should I be seing out of this setup? Top speed of your setup and what motor/ drive/ efi or carbed (2 or 4 barrel)? Do you know what your prop dimensions are?

I am cruising at 3000 RPM and moving at about 28 knots which seems a good cruise speed though im sure the new lesser pitched prop will change things.

Please advise, I did a search and turned up some miscellaneous info on props but none right on target in terms of I/O performance on multiple boats.

Thanks in advance!

Brendan.