Thermo-Quad metering rod measures

RustyRatRod said
The tube clearly has not been added. It has its own bosses on the casting. It was cast with that tube as is.

The cover casting clearly has a provision for something (hot idle compensator, two-way bowl vent) that has not been installed. The tube looks homemade, same sharp edge on both ends as when you cut with a hand tool. The base plate doesn't have the canister vent tube for two-way bowl vent installed, if it was the hole through the base plate would connect it directly to manifold vacuum.

I'm not sure about that tube, I don't see the purpose of having it there. The hole drilled through the base plate makes no sense other than what Bewy suggested.