Swapping M1 for RPM Air Gap (extra holes)

#1. I seem to have a couple extra tapped holes in the intake that the M1 did not. First is the extra small sensor (fine threaded) on the top/front.
I used one for the water temp sensor (nearest the thermostat housing), but the other must be for IAT or something I am not using with carb system.
Will plug it.

#2.Behind the carb on the pass side of manifold is a large coarse thread hole, my assumption is this is for vacuum? My PB Booster vacuum line is pulling off the back of the carb on the M1. Should I change this to the manifold? Or..............?

#3. So the water neck on the M1 is not the same as the one on the RPM Air Gap. Does the Air Gap take the Magnum water neck or.......SOLVED!

Bonus question!!!What side of these Edelbrock gaskets face the manifold, the ones with the rubber around the ports?