Problem with alternator upgrade

I installed the alternator upgrade on my 72 240Z some time ago, but continue to have one problem. The 280Z uses a wider V belt (.47 inch outside width vs. 240 Z .41 inch outside width.) The 240Z belt 7335 rides very low in the alternator pulley and at startup slips and squeals. I tried installing the 240Z alternator pulley on the 280Z alternator, but then the pulley is offset from the fan and crank pulleys. I tried using a belt sized for the 280Z alternator and that rides very high in the fan and crank pulleys. Has anyone come up with a solution or do you just live with it?