The Mercruiser is black The OMC is white
OMC is out of business and parts are scarce. They were never a Top Quality out drive. The Mercruiser is the Best. They call em Black Magic and the rule of thumb is Black on Back. I rebuilt my Mercruiser Gen II. I would seriouslly never reccomend anyone do their own. If it done correctlly it is no problem. If not it will Nuke itself within an hour.
Oh by the way I just got the renewel notice for my Boat Registration and it is 40.00 for my 1984 Searay 19'