Customs Is this GM Alternator Internally Regulated?

I am trying to use this GM alternator in my '50 pickup build but don't know if I need an external regulator or if it is internally regulated. Any help would be greatly appreciated.

 

Internally regulated

 

Thanks, that is good news!

 

If it was external there would be a spot to plug in the regulator wiring harness. Not very likely you would see one, they went to internal regulators in the early seventies.

 

- - terminals are internally regulated, l l terminals are externally regulated.

The first commonly available internally regulated alternator was used on some 1969 Pontiacs as far as I know.