@jssailem is spot on - I don’t know of any stock motor coming with an externally regulated alternator. Unfortunately not all alternators have a kit like the shown in the article John references. Additionally the kit described is no longer made. You may be able to get them from Maine Sail as he bought all he could find.
Your options are but an alternator from a Balmar distributor, buy a Compass Marine Alternator (
@Maine Sail) or research and find a alternator without an internal regulator.
I did the Kit route for the alternator currently on my Boat AND have a Compass Marine as a spare.
Les
BTW Balmar is the only one I know of that has an internal regulator as a hot standby for an external regulator. The rest of the internally regulated alternators are not compatible with external regulators.