Rather than killing the powder coating or any other such craziness just get an extended length pilot bearing. They stick out of the crank a little farther to compensate for a short input shaft. If you can't find one that fits, have a bronze bushing machined to fit the larger hole where the nose of a torque converter would sit in the crank and simply press a spec Mopar pilot bearing into the bronze. This is a fairly common solution and will move the pilot bearing significantly closer to the input nose. Good luck!