If the tag is still on the Alt you can cross referance the #s to find out what the rating is. And ditto the test it (any auto parts store) and I would upgrade the wiring (primary circuit) anyway if it is a higher rated alt.
I also ditto the you got ripped on the starter but worth it if the alt is better than the OEM 50-65amp. <img src="/forums/images/graemlins/notooth.gif" alt="" />