The 2 holes John is talking about (there's a matching pair on both sides) are where the motor mounts bolted to the engine in the early '55-'57 cars, they didn't have side mounts back then. I believe the pickups used those a number of years after the cars had gone to side mounts. As John said, use a short bolt with some sealer to close the oil leak. TIP: When you're changing a fuel pump, take the bolt out, use a longer bolt to just snug up finger tight against the fuel pump pushrod (with it pushed up all the way) to keep the pushrod from sliding down while you install the pump. DO NOT forget to remove the longer bolt before you start the engine!