Run a pressure regulator. The fuel pressure should be below 7 psi, and the closer you can get to 4.5-5.5 psi with no running problems (i.e. fuel starvation at high rpm), the better. The needle valve will be forced off of its seat in the inlet, flooding the carb with fuel, and possibly bending the float arm. In a worst case scenario, the engine gets fuel poured down its throat, and it hydraulically locks.
