Valve seat issues where with early head. Most people adding power will rework heads anyhow, especially to get the all the power out of that block. I have an 04 5.7. And have had no issue and it gets drivin and pretty hard too.
Ever notice how hard it is to get compound curves in aluminum? Works great if you fold it once but trying to get it to fit over the fender inners is a PIA. Then there is the firewall.
