EastSidinA4

I have a 1973 Datsun 240z with L24 engine and my alternator went out. How do I know that I have a 240/260/280z or 280zX alternator? I have an extra Z alternator (that is larger than the current one) that a friend gave me but I don't know what S30 car its from. (LR160-82BR) is what the sticker on the extra Z alternator says. I believe its from a 78 280z or non-turbo zX since it says LR160. Turbo zX cars say LR170 correct? Pre-78 alternators say LT150? 240z said what on their sticker? Questions are: 1) Is the original (broken alternator a 240/280z alternator or Turbo 280zX one? (so that I know if I have to do the voltage regulator mod or not) 2) Is the extra alternator that says LR160-82BR the correct one I'm allowed to used or is there a different one?