i'm sure you know the gear is what the cam used to drive the dist. the tang on the bottom is what drives the oil pump. you might cut the shaft off a old dist that chucks in the drill motor pretty easy. i am no expert on anything, but i like to have my wife turn the engine while i run the drill motor that way the bearings get a good bath. i don't do it so much that it would interfear with the cam breakin in that would be a concern. good luck.