Pilot Bearing

You should be able to use a conventional bronze pilot bushing that presses into the crank. The Zoom clutch set I purchased for my 360 swap came with a new one.

If you want to go with the late model roller bearing any truck 92 or newer with a 3.9/5.2/5.9 magnum engine uses that bearing. It fits into the torque convertor recess on the crank.