The RPM's that was posted above are well above the average T operating in the 1400-1500 range and might be ok for the mag battery charger operating in the lower RPM range. A good mag should/could be making about 35 V-AC at around 1500 RPM. There are people that charge wet cell batteries using the mag. If you are going to be operating in the higher RPM range for extended time you might think about a left side mounted gen or alternator.
https://www.modeltford.com/item/5119ALTE.aspx
https://www.modeltford.com/item/5119ALTL.aspx
(Drivers side being US cars
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