Join Date: May 2002
Location: Kingsland, Georgia
Erik, you can try an inductive amp meter placed around the larger wire on your alternator. Many battery testers have this feature for checking the charging system. Some places will do it for free like Auto Zone. This however will just tell you what that alternator is putting out, not what the rating is of the alternator. You could also check the part number and try to cross reference it. This isn't fool proof either, someone could have rebuilt it for higher output internally.
Not an exact science but this should get you in the ball park.
69' X-11 350, Turbo 350, Factory Air, PS, PB, 12 Bolt (410 gear) & NOT AN SS