Fuel pump fittings

I need help plumbing the Lycoming mechanical fuel pump. My questions are, #1, how are the fittings tightened down (not the fuel line)? Tighten the fittings and then torque the jam nut/O ring, or torque on both? #2, before I order the wrong part, what size is the fitting that attaches to the overboard vent?

Screw the fitting in to get the angle the hose attaches correctly oriented then tighten the jam nut with the o-ring.

You can use a wrench to hold the fitting in position while you tighten the nut, if desired.

The overflow is 1/8" NPT, so fitting of your choice.

Larry

Thank you!