I don't understand your question. 5/16-24 means 5/16 inch diameter, 24 threads per inch. It is the fine thread standard called "UNF". As far as I know, there is only one.

 

The "Other" 5/16-24

 

Back when I had my 1993 FL, the thread on my clutch cover was very weak when I got the bike. There was no way it was gong to hold so I borrowed a Heli-Coil kit from a friend and re-tapped the hole for a Heli-Coil. Of course, I had to remove the cover so that I could do the work on the bench. It was the first time I ever did one, but it worked fine.

This is just my opinion, but fine threads should be a no-no in aluminum castings. They do tend to strip out, even if a person is careful.