would any one here let me know my serial number on upper case shown OD 536650 IS THIS DRIVE alpha one or two.thanks

Should be a gen 2. Does it have the nipple for the lube reservoir between the two mount holes on the rt top? Randy

let me go look, what is mean rt top

Top 2 mounting holes on the right or starboard side. Randy

I look it no nipple between 2 mounting bolt on right side of upper unnit

Your serial number comes up as an MERCRUISER R.H. ROTATION ALPHA 1.84:1 ALPHA ONE GEN II Sterndrive (1991) Serial No: 0D536650 Model No: 5010184DS

http://www.mercruiserparts.com/selec...+++1991%2D1995

thank a lot for help