Plumbing coolant to center freeze plug

How do they stay in, soft AL and a hammer? Interesting, getting some coolant into the block before the heads heat it?

The plugs are oversized by a couple thou for a press fit and i was going to use green loctite. From what i gather the thought is to get fresh coolant to the middle ports before the front of the head and block can heat it, to help with the siamese exhaust ports being a hot spot.