Underneath, the crank needs a pilot bushing installed to run a four-speed. Unfortunately, not all Mopar cranks were drilled or finish sized for the bushing. Cranks that are drilled, but not finish sized, will work if the O.D. of the bushing is turned down, or often with a NAPA 615-1033 undersize bushing made for unfinished cranks. Undrilled cranks can use the later Mopar bearing 53009180 which fits in the crank's torque converter hub register, though the nose of the trans' input shaft will need to be hacked off for clearance. Luckily, the Dart's '84 police 318's crank was drilled and sized for the regular pilot bushing. Knock it in with a proper driver.