I have an 82 f150 custom w/ac, 300/6, c6 trans. Having a bad problem with belt squeal on starup and I suspect the alt is the problem. When looking at replacements thee are alot of amp choices. Any clue how i can tell what amp I have, or are supposed to have?
thx

 

I believe the options from the factory were 40, 60 & 70 (latter with AC).

If I were in your situation, I would probably get the largest amperage rating available that
physically matches up to the bolt holes & wiring.