needleand seat
When doing the initial pressure test on the fuel system, like said above, run some fuel thru all the line up to the carb to a catch can. If it is a Holley with sight level screws, remove them before pressurizing the carb. If the needle and seats are misadjusted too high or get stuck, the fuel will usually all come out the sight plug holes without going up and over the vent tubes and into the carb and engine. If there are no sight level plugs, put hose over the vent tubes and route away from the carb to a catch can.