I have an Edelbrock tripower intake on a 292. While replacing the pushrod cover gasket I noticed a small hole in the bottom of the intake manifold that leads up to another hole where the manifold bolts down in the middle on drivers side. What's this for? was there a plug that fell out? or should there be anything in it at all? THANK'S Larry.

I believe the one on top is where the automajic choke connects (if your primary carb is so equipped) 

"The Master Cylinder"

Enjoying life at the beach in SOCAL

If the manafild is for a 56 that hole is for a heat line that the 56 Ford V8s had that ran from next to exhaust manifold to the intake to prevent iceing on cool days.