90 HP 4 cycle performance

[nos3665]

1st, I run a 375 lb Mercury 90hp Optimax on my '72 Seafari. I do not have trim tabs. My hole shot is under 5 seconds, cruise speed is 25-26 mph, and WOT speed is about 33-34 mph with an average load. I get 5.1 mpg at cruise, and 3.2 mpg at WOT.

Just a Question or or 2 what size/ Pitch Prop,@ what RPM does your engine make that 90 HP?

How far from the Hull is the Lower plate on drive in height?
I have a terrible bad back and have put off repairing the transom on the 74 20' I picked up last spring but today I did pull the cover and back her up to the shop and plan to start the transom this week.
I have to use what I got which is a 1989 90 hp Force at this time.
it makes 90 hp @ 5000 RPM and weighs 304 lbs and prop sizes are Limited I hear for that engine 13.5 and 15 pitch thru 21
I may have a 17 on now I will pull and check it.
This will be my first transom job so I am not looking forward to it. feel free to jump in on advice thanks for being here Guys. BTW the way the Seas run here on a avg day running mid-range or less is fine for me.