Leaderboard

I think you’ll find they are supposed to be blocked off, when you open up the holes the water will just find the path of least resistance. the water is supposed to flow to the back of the block before it enters the head, where it then flows forward to the outlet ( thermostat) and in to the radiator for cooling . by doing what you doing, the water will just flow through the block to the first opening to the head, before flowing back to the radiator for cooling, leaving the rear of the motor to run hot, causing the head casket to fail.