MerCruiser 90747A3 87-91019A3 Distributor V8 5.0L 5.7L 305 350 260hp 898 198hp 3hp so it might have been

so it might have been an automotive application

47957 Vent Hose Connector (NOT INCLUDED)

The Part Number of lower mixture knob is 377219

Quick rundown of the parts here:

MerCruiser 90747A3 87-91019A3 Distributor V8 5.0L 5.7L 305 350 260hp 898 198hp 3hp so it might have beenPart Number(s) Included MerCruiser Distributor Assembly 97401A3 Superseded Related P N: 90747A21 90747A25 90747A27 90747A43 805185A43 805185A36 Sierra 18 5470 Newer Models Had a Distributor Mounted Ignition amplifier and this base does not have those mounts so pretty much this is only applicable to 1986 1987 & older models. Sensor 87 91019A3 Is still installed in this Superseded Equivalent Related P N: General Application Compatibility Generally found