Is Moroso A-B epoxy good stuff? Anything better?

A cracks a crack and why not enlarge it a little to give it some bonding with the material on the other side. I would think that gives you the maximum grip for the material on each side and less chance for either piece coming loose. Nothing like a hardened piece of epoxy roaming around inside your motor, might not be so pretty on the intake side if it gets caught between a valve and piston, although the stuff might just disentingrate.
Good luck