OMC outdrive from a Ford 302 5.0L interchange with a Chevy 305 5.0L OMC outdrive?

I Have a 92 deck boat with a 5.0L 302 inboard and the upper part of the omc outdrive locked up. I found an omc outdrive on a boat around the same year model and it is also a 5.0L But it is a Chevy 305 I would like to swap the whole Outdrive. My question is will it be a direct replacement or are the splines different on the drive unit. I know the gear ratio is a little different the ford is 21/18 gear ratio and the Chevy is a 21/17 ratio but I'm not sure that will make that big of a difference.