There is a world of difference in the quality of rebuilt parts out there. I was managing a parts store in the 60's and early 70's when almost all the stores were being supplied by one of several parts distribution centers, all of which bought from a nationally known rebuilder, such as Arrow, Cardone, etc. . The quality had to be there because most of our business was with professional mechanics who knew the difference and demanded a product that was right the first time.
With the arrival of the mass marketers in the parts business, with their price is everything attitude, quality has taken a nose dive. Many rebuilding businesses have been started up to supply these mass marketers with the cheapest product possible. Good products are still available but you need to go to a store associated with a reliable distribution system. These would vary in most areas but would include such as NAPA, Carquest, and others.
I had a bad experience about 3 months ago with a cheaply rebuilt item. My girl friend's Dodge van needed an alternator. She went to Autozone and picked one up. I removed the old one and had the new one completly installed down to the last bolt, that being the bolt that locks the adjustor arm. You guessed it, the hole in the alternator was stripped! I took it off and returned it to the store where it was bought. I then waited in line only to be told that they did not have another one in stock. The brain dead "counterman" finally called around and found one at another store about 6 or 7 miles away. I went to get it and the person exchanging it mentioned that he had seen this several times. Where is the quality here?
About 75% of the "countermen" I see in this type of "parts store" would not have lasted a week in a real parts store back in the 60's. I spent about 8 years in the 70's working as a district manager for two parts manufacturers with responsibility for calling on warehouse distributors and parts stores in a 6 state area. I have seen it all and the situation today is as bad as I have seen.