I am trying to determine the best starter for my boat application... Its a mercruiser 888 replacement. (Ford 302 rebuilt to marine specs)

I am seeing starters for the same application that claim to have either 9 or 10 teeth. Does this matter?

I know this may seem straight forward but apparently I have been using a 10 tooth in a 9 tooth application with no issues of stripped or worn gears. The motor however is fried which is a seemingly separate issue.

 

Interesting....
I think it's just a matter of rpm and output if the starter. Higher rpm may use a 9 tooth or lower power may use 9 tooth, but high power may use a 10 to spin it faster....
But as far as it being correct, ford offset the starter to mesh with the flywheel no matter the tooth count. The only difference is between manual and auto with the potential for the snout length to be different.