found this :
Best Answer - Chosen by VotersThe 165 is a GM 250 CID inline 6 block. These haven't been produced since about 1980. The modern equivalent is the GM 4.3L V 6, used by Merc, Volvo, and OMC, the basic 2 bbl carbed model producing 175-185 hp. Too bad they changed, in my opinion the old inline 250 was the best small marine inboard engine ever made.