Fuel Pressure Test fitting size?

[INK DEMON]

I'm looking at doing a fuel pressure test on a 4 cylinder. I still need to buy the pressure tester and after shopping around for a while I can't seem to find any info on the size adapter I need with the kit. Does anybody know the size/thread pitch of that tube that the pulsation dampener screws onto?
Thanks

 

[xci.ed6]

We don't have one (v6 for sure).

I got one of those things that replaces the pulsation dampener with a valve stem thing.