We were doing a leak check at the end of the annual condition inspection. With the throttle open, fuel pump on and mixture full rich, I had fuel coming out of the #4 intake manifold (at the gasket) and eventually out of the air box. I have the Silver Hawk EX-5VA1 on an IO-360. The spark plug was dry. Clearly I will replace the intake gaskets, but what has caused this? I suspect a problem with the "flow divider" (where the injector lines come from) but is this likely? Any comments appreciated.