definitely put a straight edge on the block as well.

Now that the problem has been found, the big question is what caused the failure? This is probably something your not going to want to rep[eat very often (especially if it only lasts 30 something miles). Something caused this issue, I wouldn't call it fixed until you can identify the original cause, and make sure that was addressed.

It would be pretty unusual to have a blown head gasket without having a damaged head, or a damaged block, or both being damaged. Sorry.