I don't think the older ones did, but you should be able to fit one....I havent seen it anywhere, but ill take of the drive for service the day after tomorrow, so ill look again, do all gen II drives have a monitor?
91, 92, and the early 93 Alpha I Gen II drives didn't have them, nor a way to install one like in use with the newer ones. No place for the check valves in the bellhousing, the drive, or the fitting thru the transom shield.
Those drives do have a dipstick in the top of the outdrive cap.