Recently changed the fuel sender on my 56 pickup.The truck started and ran ok before I changed the sender(all be it 2 weeks ago when it ran last).Now it won't start.Had a look at the spark plugs and they were dry.I took the fuel line off where it enters the carb(2 jet Rochester)and fuel spat out with some air bubbles and seemed to be under pressure.What can I check next.Could the fuel line be air locked and how do I clear it.Anything else I can check.Thanks in advance.