This video came at a good time for me and I watched it with interest. I fixed 2 similar cracks in my 8BA block a couple of years ago. (
https://www.fordbarn.com/forum/showt...hlight=Eagle43). I got the truck finished last fall and the motor ran fine on two outings. Earlier this summer it suddenly lost power and ran rough. After trying all sorts of solutions and narrowing it down to having no compression in cylinder #2, I finally pulled the head and discovered that the hardened valve seat I had installed had come loose and was rattling around. The fixed cracks seem to be holding up fine and are almost invisible. I bought a new valve and valve seat and am waiting for the Permatex 64000 high temperature sleeve retainer I ordered online. I think this is the stuff they were using in the video. Loctite 640 should be similar.