I used the 3 position manifold from Van's that I bolted to the firewall. I ran a hose from the AN fitting in the #3 cylinder to an AN fitting that attached to the bottom of the outer position in the manifold. (Be sure to put the fitting in the manifold before you bolt it to the firewall. Ask me how I know

)
The pressure sensor screwed into the opening perpendicular from the firewall. I used the top opening to feed manifold pressure to my ElectroAire electronic ignition control box, but you could just use a plug if not needed.
I used the other two positions on the manifold in a similar manner. Oil pressure hose to bottom, oil pressure sensor to middle, and oil pressure switch on top to turn on Hobbs meter and turn on/off oil pressure idiot LED in instrument panel. The fuel pressure hose went to the bottom of inner position, with the sensor in the middle position and a plug in the top.
If you need a picture, I will take one and post it.
Hobby
RV6, slider
O360-A1A C/S