ALTERNATOR question about the the pulley
 

I have a 89 RX7 and the alternator is on its last leg, I just picked up a fresh one form Mazda, the both look exactly the same except the ne one has a pully on it with one grove for the belt. my old one has a pulley with double groves for Two belts. Did they give me a alternator for a diff year? Or do i have a alternator thats not suposed to be there? Is it possible to take the pulley off the old one and put it on the new one?

The dual belt alternator pully is an aftermarket part. Transfer it to your new alternator. :)

Thanks , i should have known better, but do i need any special tools? I see that it spins freely

youll need like a power tool something that has torque so it will break it loose before it can start spinning freely...
TwEaK

Rattle gun for sure. If you don't have one, just take both alts down to your local garage, and ask them to do it. It'll take 'em 2 minutes.

That's exactly what I did when I swapped to a gilmer drive pulley.