What valve springs should I use?

Just the word "Cracked" next to heads has everybody freaking out as if there junk and you now need, sorry, I ment "NEED!" New heads.

Everyone acts like it is the end of the world and you have the cooties!

Even the older heads crack. 308's, 302's, X-J-U, Poly heads, HEMI heads, 906, 452's, they all crack. Not every head cracks, but you would never know unless it leaks water and they normally crack where there is no water. And that is part of the reason they crack.