My Stealths are the fiorst ones made.No problems after all these years.I did have locks springs,retainers changed because of my .588 solid cam.Machinist who was a perfectionest said they all looked good.He did back cut the valves and open them up some.Dont matter what head you buy they shopuld be checked.Heard quite a few Eddys that werent right out of the box.Rocky