Fuel sprayed out of hood onto windshield....Help!!

crackedback said
It may be siphoning fuel out the carb vent tubes. Hook a small piece of hosed to each vent, making an arch. Cut a V at the top. See if that helps

It's not likely fuel pressure, unless you have dripping from the boosters/flooding at idle. If the system is stable at idle, that's the place where you see pressure overcoming the needle/seat and float assembly.

Damn beat me to it. At 80 MPH you may have created a negative pressure across the top of the vent tubes and drawing the fuel out of the bowls, especially since you said the air cleaner was off. Do the rubber hose trick that Rob suggested, that's an old school trick that I was taught some 42 years ago.