I tried a voltage reducer but it didn't work well for me, so I went with a new 12v motor from Brother's Trucks (which is apparently now part of the Holley family) if I recall: https://www.holley.com/products/ac_and_heating/blower_motor/parts/HTRM063
It might have been Jim Carter Trucks: https://oldchevytrucks.com/el116.html
I think the shaft was smaller than the original so the new motor came with a sleeve to adapt it to the squirrel cage. Been working great for years.


1949 GMC FC253 - 1 Ton Dually
1966 Buick Wildcat Convertible