? For all you Porsche alternator guru's

[Supa Ninja]

I have a 11 blade assembly w/ a bosch alternator. The only numger on it is 0 120 400 522. I have no clue if it's internally or externally regulated. If externally I'll need a regulator. I measured the pully and it's the 3.75 one. I tried search all over the internet for a some infor on this alternator and came up with zip. I also searched this website and still no more answers. Hopefully soemone can help me.

Nick