It was roughly 1990 when they switched over to 1-piece rear main seal engines will measure 3" across between the bolt holes on the crankshaft vs
5hp with Serial# 3021732
Some bolts and other parts included
TOP COWL AND SUPPORT BRACKETS (1250)
Mercury Kiekhaefer Outboard Mark 30 Saddle Mid Section Rubber Mounts 25150 25151 Camshaft It was roughly 1990 whenThis is Off a Mercury 1956 Mark 30 1 4 cylinder Turbo Four (serial # 994104) May work with 1957 or 1958 Item Condition: Good Working Condition Rubber is good Part#'s Rubber Mount upper (small) 25150, 25152, 23727 Rubber Mount Lower (Big) 25151, 25153, 23756 Other Related Models: Mark 30, Mark 30 1, Mark 30 2, Mark 30 3, Mark 30E, Mark 30E 1 Mark 30 2, Mark 30, Mark 30H 950250 and below, 984920 thru 102598, 1031987 thru 1163545, 1163546 and upars