Very cool!
Try a new belt, if it's still close to the end of the adjustment, just get a slightly shorter belt.
Used to be for old school GM alternators from the '60s and '70s you could buy kits with higher amperage windings to put in them (and might still be, I haven't looked for this in a long time) . I wonder if there are any higher output alternators out there that you could swap the guts into a stock case?
