Re: Off topic- looking for a 5/8"x20 NSC cap/plug to block breather...
When I wrote that piece I used 'NSC' top denote 'non standard cycle'...That is noted somewhere in the details I believe...
'Non Standard' refers to the fact that many people believe incorrectly that Cycle Thread is 26 tpi at all diameters and in all applications...That is not the case....
So, the thread you need is Cycle Thread but in the 20tpi format...Ian