360, LA360, or Magnum 360?

Thanks again, guys....

So here's one question that has been lingering for me.

Assuming you find a clean, documented Magnum...but the heads are cracked.
Does this mean the heads are automatically garbage? Assuming they don't leak, can you still run them? It sounds like people get huge mileage out of the Magnum motors so when do cracks become a problem?

BTW, I can't thank all of you guys enough. This forum is amongst the best I have seen. You guys are generous with info....and have spectacular taste in cars too! :D

I'm checking out the '73 LA 360 tomorrow...but if it's a piece, I'm back to looking at Magnums. :)