OMC 0313171 Bolt Screw Water Pump Impeller Housing Stringer 6-in High-Profile Thermostat Housing Parts Impeller will need to be

Impeller will need to be inspected

Found on 1976 ONLY V8 applications with an "M" suffix model

I'm quite positive that this is what there is as it only looks like they produced 5 different gear pinions of this "look" that basically varied in lengths and some had an extra hole on the bottom for some sort of pin

Gas tank Bracket:

1965 1966 1967 1968

OMC 0313171 Bolt Screw Water Pump Impeller Housing Stringer 6-in High-Profile Thermostat Housing Parts Impeller will need to bePart Number(s) Included OMC 313171 0313171 Housing Screw Bolts (For High Profile Gearcases) You get a set of 4 as pictured & Includes the lock washers as pictured Superseded Equivalent to 321577 0321577 354101 0354101 358240 0358240 363011 0363011 General Application Compatibility Found in OMC Stringer High Profile Upper Gearcase Assemblies 1970 1977 120hp 155hp 215hp 235hp etc. models using a High Profile gearcase Other Details Freshwater Used Parts