I just got an oil pressure guage but the intrustructions say I need an adapter for it to work. I've found 3 sizes for them:
20mm 1.5 Thread
3/4 unf-16
18mm 1.5 Thread
I have an st if that helps any.
20mm 1.5 Thread
3/4 unf-16
18mm 1.5 Thread
I have an st if that helps any.