Some words of advice if they're used heads you want to go through them to clean them up and look over them... why would you not change the valve stem seals if you're there?
Because they are essentially brand new and I didn't know that they could be damaged by the valve being pulled back through.
I've thrown enough money at parts that I'm to the point that "while I'm in there" isn't a good enough excuse anymore. I'll look them over and if there is any damage I'll order some more in.
