The crank was almost certainly from an automatic car, but the cavity looked deep enough for the input shaft nose.
DING,DING,DING, all of the OEM 1962 to 1974 RB, 413, 426 and 440 automatic crankshafts I've dealt with are not machine the correct depth or the correct I.D. for the stock length input shafts for the OEM NP 833 trans. and the stock Mopar pilot bushings. NAPA use to make a adapter pilot bushing that could be installed into the automatic cranks but that doesn't solve the depth problem
Slide the tranny out and measure through the clutch disc with a thin tape measure to see how far it is into the bottom of the cranksahft pilot hole to the mounting surface of the bellhousing and then measure the length of your input shaft to the face of the tranny face
I do know of several other Mopar racers that had thier input shfts shorten so they could run the automatic cranks with the NAPA pilot bushings
