UH Oh.

What does the inside of the lifter bore look like there? Does the crack extend to the inside? I tell you what I would do if you cannot see the crack inside the lifter bore. Take a small hand held grinder and gently dress where the "crack" is. See how far into the casting it goes. It may be that you grind right through it and grind it out, because it could be right on the surface and simply look worse than it is. Certainly worth the 10 minutes to try.