Thanks, I'll check it out.

I was thinking about pushing block sealer into this crack with a grease gun through the head bolt tap, then I would chase a tap through the head tap before reassembly. My thought is that it would give it a head start and then when I had the head reinstalled I could run block sealer again through the cooling system. I'm wondering if it might not be better to remove the thermostat or plan to replace it immediately.

Thoughts?