I have a 72 gmc pickup truck with a 350eng and a edelbrock 1406 4brl carb.the problem I am having is while driving the fuel is getting to the carburetor but after about 20min it starts to cut off then it just cuts off,at first I thought there was air coming into the line from the gas tank to the fuel pump so I replaced the line,but it still cut off so I changed the fuel pump and still cut off so I took the top cover off the carb and cleaned it out and adjusted the floats and still cuts off.plus my carb is about a year old so now I don't know where else to look,so if there's anyone who can help me with this problem please do