Looks like it takes an HEI cap, but no distributor gear?
Can you tell how many lobes on the reluctor? 4/6/8 cylinder may be a clue.
Any clue as to who made it? (manufacurer?) No label, part no? Heck for all I know it could be some sort of custom drive off a cam, IE front mount injection pump style.
Looks like it's from an Oldsmobuick! Probably off a DeltaLesabre model!
Looks like an Oldsmobile distributor with the gear pulled off.