Gear ratio question

[Kentj]

It is a long story but I have ended up with the wrong gear ratio for a repair job on my outdrive.

I purchased a used top end sold as setup for a V8 turns out the splines on the gears count out at 17/19 which as I understand is 1.84 - my question is can I run this ratio on my 5.7 which was setup at 1.5:1 and what is the down side? - I boat mostly at altitude near or above 4000 feet.

Thanks in advance for your help

[Jango]

Not really a problem, unless you run W.O.T.

With a 1:84 to 1 gear in place of a 1:50, your engine can run up to 1000 rpm higher than with the 1:50 gear. In order to get back to desired RPM range of 4200 - 4400 you will need to change props ADDING about 5" of pitch to what you now have. i.e. from 19P to 25P or if you have a 21P go to 26P. Going to a 4 blade prop will also help - same as adding one inch of pitch if same dia.