Exactly. There's several gallons of water in small passages surrounded by cast iron. When it gets cold, it's cold all over, not just at a small opening. For every person who may have got lucky with a core plug blow out at freezing, there's hundreds of stories of shattered blocks/heads. Personally, I've never seen or heard of a story of a saved block from core plug push out. It's my belief that the freeze plug thing is an old wives (mechanics) tale myth, started by people trying to explain their existence without knowledge of the casting process, and it got passed down thru the generations. Just my 2c.

 

Got the new 30mm brass plug in. We'll see if it holds. Wasn't a lot of room under the truck to tap it in. Not too excited about these heads. Probably will start shopping around for new ones. Meanwhile, I'm gonna drive this bitch like I stole something and see if I can destroy her again...

 

Glad you got it fixed. Hope it holds.