You might want to consider some options in going down the alternator road....
I have one of L.D. Becker's alternators, and its fine, with a reasonable price, but, I think I got what I paid for.
On the other hand, I purchased two Nu-Rex alternators, 6 volt, but they are rated to 60 amps. If I were to install halogen bulbs, then a 60 ampere alt would be preferred. Now, I also purchased the alternator bracket from the Filling Station to mount the Nu-Rex units, and its a v. nice bracket to work with.
These two units were installed into the 1928 Chevy Roadsters, and work v. well.
Nu-Rex has a site at Hershey in October, perhaps other places as well, and his Hershey on-site price is considerably less than his online price, I think I paid 140 dollars for a 60 amp unit. Its also a one wire hookup, etc.
Maybe this coming Oct., I might buy another pair of alternators from Nu-Rex at Hershey, but for now, the generators on the 1932s are working pretty well and it can wait.
http://www.nurex.com/Ciao,
Jay