The wide belt pulley is available on Ebay- - - - -lots of farm tractors have been converted to GM internal regulator alternator charging systems, and 5/8" pulleys for Ford, Massey-Ferguson, Farmall, etc. are a bolt-on swap.

Just looked- - - -there are several alternators with 5/8" pulleys already installed for under $100.00. Pulleys are in the $12.00-$20.00 range. Search "5/8" alternator pulley".
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!