Cadillac: 71 Cadillac 500 Fuel Pump Vent/Vapor connection, chev truck, gas tank

Question
I have installed a 1971 500 cadillac motor in a 1969 chev truck with a vented gas tank. The fuel pump has three connections. In, out, and what i'll call a vent/vapor connection. When the engine is started there is pressurized fuel at this vent/vapor connection.  Is this normal, and if so can I plug this connection, or do I need to route it somewhere.


Answer
If memory serves, Since your gas tank is VENTED via the gas cap or some other maens you can plug it off.

That is a fuel and vapor return line that goes back to the fuel tank. See if your fuel tank has 2 steel lines coming from it and you can attach this vent/vapor line to this other steel line which is a RETURN line.