Alternator questions
First off, have you converted to 12V? If so, just about any newer alternator can be made to work electrically.
An alternator is essentially two parts - the rotating armature and coils make the current, and the voltage regulator adjusts how much current they make. The voltage regulator will adjust the actual output current from whatever alternator you choose so that the system voltage stays where the regulator is set - normally between 13.5 and 14.5 V.
Most alternators have the voltage regulator built in or bolted on the back, although I have noticed some that use an external regulator. Although you can pick an alternator with a current output that's too small, you really can't go wrong by choosing one too big. You will probably waste some money, though, if you choose a ginormous model.
The details of the wiring for an alternator can be simpler than a generator but you'll have to make sure you get good instructions if you aren't handy with this sort of thing.
As you mentioned, you may have to fab a bracket if you can't find a bolt-on part.
I needed to upgrade my alternator in my '59 for stereo system (and piece of mind to get rid of the '68 alternator on my rebuilt '68 302 motor)!
Anywho.... I got the PowerMaster 140-amp, model #8-37140 from Summit Racing. Wasn't cheap ($260), but it performs very well and the chrome looks good and is holding up fine. I'm sure they have something for your 390. Just check out them and Jegs on the Internet or call for tech support (quicker if you're slow on the computer like me):
Summit: 1-800-230-3030
Jeg's: 1-800-345-4545
Plenty of other places, but you can always start with these two, get the info, and go shopping prices and availability from there!
Good luck,
Daryl




DJ
