Adding a water pressure nipple - F250

[Winspt]

Hello - I'm adding a water pressure gauge to a boat with an F250 (2009)
Any idea where I would install the nipple? I'm sure there's a plug that gets removed some where
but I don't want to guess.
THANKS!!

[boats.net]

It's on back of the 4.2L engines
WaterPressurePort 4.2L.pdf

[Winspt]

Thanks

Thanks super moderator!!