I would like to know

Well, are the Magnum heads cracked? Let’s be sure in this and not just run at the mouth that they all crack. While I’m sure this could be the case. Where are they cracked? I’ll tell you the cracks are at the thin spot between the valves where the metal is solid. The cracks themselves aren’t a nice ending experience nor do they hinder a working engine.

I’ve taken apart a sub 80K 5.9 with cracks. I also seen 300K 5.9’s still motoring on down the Hwy. I’d bet there cracked. While I won’t say “Sure! Use them cracked.”, I have and have zero issues.

The Magnum head is a boost in power via better ports and a smaller chamber. They have a larger intake valve than the typical 1.88 J head & of course the 1.6 rocker over the 1.5 of the LA head. If you get over the non issue of the crack(s) in the head, it’s an inexpensive winner.

But don’t worry, LA heads crack as well. Not as frequently.