Atmospheric pressure
To the intake manifold.
On the intake manifold
Follow the intake air plenum from the air filter. It connects to the carburetor. The carburetor is mounted on the intake manifold.
from the intake manifold.
Under the hood, on top of the intake manifold.
On an engine bolted to the intake manifold.
Usually it's bolted to the top of the intake manifold.
It is a small 'L' shaped hose that goes from the side if the water manifold to the bottom of the carburetor intake manifold. I believe it is part of the water supply to the carburetor manifold that heats it.
Gravity and vacuum. The air flow into the engine creates a vacuum that sucks the metered fuel from the carburetor into the intake manifold and from there through the intake valves into the combustion chamber where it is ignited by the spark plugs.
remove the intake and exhaust manifolds. there are bolts that attach them onto the head and there are bolts near the carburetor that attach the intake manifold to the exhaust manifold.
I think you will find that this truck is fuel injected and has no carburetor. If I am wrong and it has a carburetor it is mounted on top of the engine dead center on the intake manifold.
Probably not. Unless the previous intake and carb were not functioning properly.