I started a thread maybe a month or two ago talking about at these new price levels it doesn't make sense to put money into cast iron heads especially when you can get a fully loaded set sent to your door for $703... I have way more into that into my 596 heads.. K line valve guides, stainless steel 202 valves, Crower Springs, chromoly retainers, competition valve job, a couple hours Shop Port time, plus days worth the porting of my own...