It is a vacuum tree. One line will be for the transmission modulator, One is for the Air Conditioner reservior tank and the last is the vacuum sensor in the thermostat housing.
leaking or cracked manifold
it could be a leak coming from the chamber behind the water pump just beneath the exhaust manifold. too much labor
counterclockwise
The gasoline goes to the carburetor, not from it. The butterfly valve and float assembly regulate the amount of gas going into the carb, and the air/fuel mixture regulates the amount of fuel gets into the intake manifold. I hope this answers your question.
Directly behind the intake manifold with 4 10mm bolts on each corner, there is a 1 inch thick black vacuum hose coming out of the the bottom and 2 clips with wires attached to it coming from it as well
Where is the leak coming from. Most likely you will need to replace the exhaust manifold gasket which will require removing the exhaust manifold.
person coming from behind
there are 2 sensors 1 is in the exhaust manifold at the very front with 1 wire coming out of it and one behind the catalytic converter with 4 wires
right behind the rad...mounted on the bottom of the exhaust manifold (big silver cover) sticking out with two wires coming out of it...looks like a sparkplug
The intake manifold.
the intake manifold is what takes air coming from the intake and directs it to each intake valve in each cylinder
Because the tube (hose) is defective and needs to be replaced. That tube is coming directly from the fuel filter being pumped by the fuel pump to the carburetor. Replace the tube/hose or you WILL have a major engine fire and/or huge KABOOM.