1976 gmc 350 - no fuel getting to carb, I disconected the fuel line from the carb & cranked - nothing came out but I could heaar the pump working and feel some air being blown out - yes there is fuel in the tank. Do you think its the pump?

Yes it is probably the pump or a problem in one of the fuel lines but i would bet more on the fuel pump or suction line into the tank. If you can take the line off going to the tank put it in a jug of gas and see if the pump will pump it to the carb or the engine will run.

If you can feel air blowing, it could be that the suction tube in the tank has broken loose. I guess to check it you either have to drop the tank, or hook an electric pump to the gas line. If the electric pump will draw gas, then the tube is okay. It may be just as simple to try a different fuel pump. If that one won't pump, then you know the problem is in the tank, or in the gas line. Be sure the connections are good and tight before you try anything else. It may be sucking air because of a leak in your gas line, or fuel pump connections.

That should have a manual pump on it its prob a bad pump, or there a hole in the fuel line coming from the tank and sucking air!!!

Yes....and the fuel strainer on the sending unit in the tank may be plugged up also.