One important item. Rebuilding is pretty straight forward. The real problem in the industry is the replacement parts. Far too many aftermarket repair parts are little better than junk.

Some rebuilders source good replacement parts. The majority of the mexican rebuilders do not in my opinion. Most chain store alternators and starter rebuilds are coming out of mexico.

So the answer to your question is your local rebuilder using good aftermarket parts or the junk lines. You can ask him.