Help identify piece

Hello Mopar community, I have about a month with my first classic mopar car( 1970 Dodge Dart Custom) it’s been running pretty good until it didn’t, so I’m gonna start the rebuilding process( again this is my first and also I’m very young/inexperienced) I have changed the belts, the alternator, starter, battery cables, the voltage regulator, ballot resistor, and now I want to change this piece that goes on top of the engine block I don’t know the name, so please don’t eat me alive on this one.

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