[Shaggy]

Okay if you can get them to pay for it then I would make them replace the piston that got hit and fix the heads. and should fix all the damage that would normally be done. Unfortunately if you are experiencing coil bind then what that usually does is wipe out the cam in short order.I still stick with my first instinct of the valve guides be set-up to tight. but what ever the reason make sure they at least fix your head and if they won't replace the piston that got smacked then they need to at least radius the sharp edges from where the valve hit it. If the do the latter I would never put any dope on it because while it would be considered a serviceable part it has weakened crown of the piston. I have run boogered pistons before from dropping a valve and the only real configuration I have personnaly seen any real trouble with it is on Nitrous because it hits instant on unlike of types of induction.

PS if it is not radiused then you will have hot spots that will usually lead to pre ignition.