Sounds like a crazy Q, but I want to build this so I need to make sure that I get the right adaptor.

http://www.lafishmag.com/LeakDownTester.html

edit: is M14x1.25 correct?

 

Can anyone confirm m14x1.25???

 

Yes you are right M14-1.25 is the correct thread size, I know this because I have had to re tap my cylinder head on my Saturn motor before, because when I was swapping in my new motor for my Saturn that had 27,000 miles on it, I put in new spark plugs and found out that someone at the factory had cross thread the spark plug, but I got lucky and fixed the thread, but it was just a little weaker than the rest but never have had a problem with it again.

 

thanks

 

No problem glad I could help.