I have the 120 amp alternator that used to be available from Mancini. I have newer harnesses in my car and various loads that you don't have such as fans. I put the a/c in my car and have had no problems so far. I will say that since I upgraded my battery doesn't drain down anymore, so my alternator was questionable anyway. I did the MAD electric modification to the car, that was also helpful as far as durability.