BMW: alternator 140 amps?, bmw 525i, dead battery

Question
i have a 1991 bmw 525i . not really that much in to cars is that a e30?  6cyl. 5spd whats the difference between the alternator sizes? will a 90amp HURT the car instead if the 140amp it calls for? Thanks for any and all help..

Answer
Phil,
 If you've noticed, 5-series have changed over the years, you can buy a 525i right now, but it will look far different from your car.  So in order to make sure what bodystlyle car you are talking about BMW gave them E-codes.  The E30 is a 3-series from 1984-1991, while your E34 had the body style from 1989-199x?

 I dont think the Alternator would "hurt" the car, however it calls for a certain amperage, so I think I would stick with it, even if it is slightly more expensive.  It would be like you only eating breakfast and skipping the other meals.  The battery probably wont be charged correctly, and will lead to a dead battery eventually.
 Hope this helps,
 Josh