Magnuson supposedly makes nose drives in different lengths for the M series, bu they're pretty expensive. Some GM ar really long, but of course not the correct length, and can be shortened and the bearing moved.
An alternative is a jack-shaft in parallel (as used on the Ford Super Coupe) to have 1 pulley align with the engine/damper, and the other with the M90 nose.
More: read my article:
http://victorylibrary.com/mopar/blower-drive4.htm
