them engines are designed to push the core plugs out first before any damge to the head or block when the water chambers freeze.water exspands when frozen thats why they call them exspansion plugs or core plugs
them engines are designed to push the core plugs out first before any damge to the head or block when the water chambers freeze.water exspands when frozen thats why they call them exspansion plugs or core plugs