1983 Dodge Truck unknown flooding!

Hi, I was installing a new distributor on my truck and unhooked the metal fuel line from the carbuerator, I have the timing set correctly now. But now when I try to crank the engine fuel comes out of the top of the carbuerator and it floods out. The FLOAT IS NOT STUCK! I took the carb apart and made sure everything was right. I can pinch the line where it is rubber and crank it and it will run fine until it runs out of fuel. Then as soon as I undo the vise grips and allow the flow of fuel to the carb the engine dies. What could this possibly be! I never had this problem before and did not modify anything.