I just put an alternator on the 39 standard. . The radiator fan is mounted to the alternator pulley. Everything works great except for the noise from the fan now. It sounds like a prop job on take off. I realize the fan is spinning faster due to the smaller pulley but the noise is awful. If you take the fan off it is quiet like normal even at half throttle. Could there be some kind of turbulence or something between the radiator fan and alternator fan fins ? It's too noisy to drive. It's a 4 blade 16 inch original fan. I want to leave the alternator on and I'm looking for suggestions. Thanks for looking.