Easy off is evil, it turns aluminum black and it STINKS, use Simple green. Believe it or not the stuff work's awesome, especially if it's warmed to around 100 deg F. Takes off carbon, grease, whatever just let it soak for a day, little scrub and wash it off with water. Heads come out looking like new. Check the simple green website though I can't remember how hot you can get it before it loses it's mojo, I think it's 120 deg f. And it's apparently enviro freindly too.