Early 70 350 w/ vortec heads stock cam and Edlebrock carb.. ran for 4-5 months and started overflowing fuel out if top of carb/ vent. Put new carb on same thing. Pinched fuel line from mechanical pump and blew out the pump weep holes. Bypass mechanical with an electric pump4psi with 3rd carb same thing. Doesn't overflow sitting cranking over as soon as is starts and runs it overflows.. replaced mechanical pump and put fuel pressure gauge it was 8psi before it blew out that pump also?????? Help