Do you know how many guys are running these heads with the valves and retainers these heads come with. They even come with 10 degree retainers and keepers not the cheap azz 7 degree stuff Edelbrock puts on their heads.
I am sure lots of them. I know when I bought mine there were stories of dropping valves etc. or tight guides like the Eddies. I am sure you could get by with just having a shop go through the head just like everything else.