I would endorse that. Even if they show cracks on the surface. You'll just have to hope they crack farther. That's the thing about cast iron. You just never know. I hope you find some uncracked ones, though. They're out there. You might even try Allied Cylinder Head. They have reman Magnum heads for 632 including the gasket set. But you need to call them and verify they have the 5.9 heads. They seem to lump the 5.2 and 5.9 heads together on their site, and that's incorrect.