oh, 90amp rebuild upgrade. my bad.

http://www.4x4wire.com/toyota/tech/alternator/

 

As far as i can see there is nothing different between the MR2 alt and 22RE alt, the electrical conections are the same, the only difference i can see is the pulley, and that can be changed, other than that its just a matter of making it fit in the stock mounting brackets. if there is something im missing then let me know.

 

i think its just the mouting brackets that are diffrent. the mr2 alt will bolt up to a 3vze all you have to do is add a inch to the adjuster bracket

 

One other thing about the '1 wire' GM alt is that you'll lose the light on the dash telling you it's not working. The toyota alternator's regulator takes voltage passed through the indicator light on the dash and grounds it when the voltage output drops below a certain threshold thus turning the light(s) on in the dash.

 

My 86 4Runner has a 22RE and i should be able to to make the MR2 alt work on my truck as well, Its just a matter of moding the mounting brackets a little to make it work.

 

You can have your stock alt re-wound to a higher amperage, and it would prolly be less than trying to mad a GM or MR2 version.