Help with this edelbrock manifold

At the front passenger side of the intake, the smallest hole os for the temp sender.

The larger hole next to it can be used for the heater core. Or it can be used in conjunction with the drivers side hole for water return from the back of the engine via drilling and tapping the intake to remove water from the back of the head.
Maths holenin the intakes runner can be plugged or used for a vacuum soruce for power brakes if your carb is not so equipped with a brake booster vacuum port.