Alternator mystery

Hello everyone,

It has been ages since I've posted anything! I'm having a spot of trouble finding out information about the alternator I need for my Golf - it's a 1989 cabby gti.

This may be really simple for some of you, but I know very little, so any help would be greatly appreciated.

I've been told I'll need either a 65 amp or a 90 - I've had a look at the alternator which is there already, and the sticker has worn and it only says Bosh. Does anyone have any ideas?

Thank you in advance! 

65 will do here is a link to one on ebay
http://item.mobileweb.ebay.co.uk/viewitem?itemId=121033362978&cmd=VIDESC

65 will be fine, 90 isnt really needed unless you have aircon, diesel or mega stereo