Thermostat housing different sizes...
Zero V8 engines used either of the Slant-6 thermostat housings.
It means whoever put that cattledog together got it wrong. There were two (and only two) kinds of Slant-6 thermostat housings for all 170, 198, and 225 Slant-6s built throughout the world. Almost all of them used the kind shown on the right in that cattledog page cut (and in Badvert65's photo), except '60 cars with power steering had a very similar housing but with extended bolt bosses for the support bracket for the alternator (Valiant) or the P/S pump (big cars):
Zero V8 engines used either of the Slant-6 thermostat housings.
