1976 Ford F250 Fuel issue
 

Truck was driving fine and just died and when I start it the truck runs for 10-15 seconds and when I give it gas it just dies

I just replaced the fuel pump and the carb is recently rebuilt

Truck does have duel tanks

When it dies, remove the air cleaner and look into the carburetor while working the accelerator linkage. You should see fuel squirting into the carb bore(s).

If you don't see any fuel squirting in there, there is a fuel supply problem.

Could be,
Pulling air in somewhere in the fuel lines
defective pump
restriction in line from tank, switching valve or line to carb.
You didn't say if one barrel carb or two barrel, but you should still see fuel squirting out the jets when working the linkage.
If you do see fuel , will it start if you hold the pedal to the floor when attempting to start the engine.

I will try all of these things tonite when i get home. I'm very green as far as engines are concerned but I believe it's a 390 so not sure if 1 barrel or 2 barrel

With a 390 it can't be a one barrel, so must be either a 2 or 4 barrel.
The check remains the same no matter the size of the carb..