[Brian]

I ran a 3 brush generator for years on my daily driven 35. Man that was an exceptional generator....wish I still had it. It would push more than 30 amps; push the ammeter needle off the scale, but I digress....
Thing is, these things are so simple. I ran the cover band just sufficiently loose to enable it to be easily slid back. I'd move the brush up for daytime driving, enough so that the ammeter indicated about 3 amps charge at some engine revs. Come nightfall, stop the car at side of road, no need to even switch off, slide cover back, move brush down so that ammeter indicated about 3 amps charge with headlites on and a few engine revs, slide cover back. After a while, this becomes second nature, and you 'know' just how far to move the brush to suit each application. Never, ever gave any problems in hundreds of thousands of miles.

As I said, it was an exceptional generator. Would appear, reading posts on here, that this style of generator is very limited in its output...dunno. I only changed it out when I [so wisely- yeah right!!] went 12 volt with an alternator. When I was a rodder. Now gone full circle again and running 3 brush.