87 chevy won't start

[rick222]

Pickup has two fuel tanks but have only used
the passenger side tank the whole time I have owned it
(the other tank doesn't work)

Today, truck turns over, lots of juice, but no go.
Seems like its not getting fuel.

Flipped the fuel tank switch on the dash several times,
thinking it might have got bumped to the wrong tank.
This has happened before.

Still won't start.

Is there any manual way to force the gas feed from the passenger side tank?

I figure there must be a manual valve to switch the tanks somewhere.

Looked all over the place but can't find it.
Is there a way to change tanks manually from the valve
under the truck by the tank?

Any suggestions would be most welcome.