at this point I do not plan to go as far as the bellows.

I will do all bellows and cables in the next phase.
(Unless this phase mandates.)

First things first, I need to get her fired up and in the water.
if all runs well and sounds, looks, tastes good I will go the next step.

I'm not finding my number on this database ...

OD651968

Me either...not finding a series that starts with "OD"...could we be missing something ? If it were "D6511968" it would be a '87~'92 Gen ! Alpha from a 170 HP V6...probably a 1.65 gear...but the "O" puzzles me.

OK...did some digging and went to Mercruiser Parts http://www.mercruiserparts.com/r-mr-...rive-1983-1990.

Based on the numbers yours could be an Alpha I in the 1983-1990 series of production. Also...if I plug that number in as zero D it comes back as a 540 HP Big Block so it's not that. LOL

Good Luck

the Marine folks here looked it up (somehow) and said it was a 17 July 1991, 1.50:1 RH unit

OK

I just looked itr up here:

https://www.perfprotech.com/mercury-...g/searchserial


and I got:


Serial Number: OD651968


Product Line: MERCRUISER

Year : 1990

H.P.: ALPHA ONE

Model Number 5010150CS

Model Description: R/MR ALPHA ONE STERNDRIVE


MERCRUISER 1990 ALPHA 5010150CS R/MR ALPHA ONE STERNDRIVE

OK...so now you know.

Next question ... will the Alpha One's mount-up to the MC-1 Gimbles

I know of no issues doing that. I did it on my '79 Formula be fore converting to Bravo I's and it was plug and play. I did change the U-Joint Bellows when I did it because one of mine was torn. Also a good time to take a look at the Gimbal Bearings. If you have torn u-joint bellows you get this:

[IMG]http://i705.photobucket.com/albums/w...r/DSC_0383.jpg[/IMG]
[IMG]http://i705.photobucket.com/albums/w...r/DSC_0379.jpg[/IMG]
[IMG]http://i705.photobucket.com/albums/w...r/DSC_0378.jpg[/IMG]
...so check your U-Joint Bellows carefully for any signs of leakage.

Roger that! I will check them out!

I was told the drives would bolt-up

I was also told they would bolt-up but are shaped differently and would not look good (and may leave a gap for water to get into.

No...they will look good !!