Got back on the Vette today and got the drivers side head off that dropped the valve when the keepers came out. I'm thinking the rocker somehow got twisted and was on the valve cap, not the valve itself, and the keepers jumped out. Piston looks good, just a little wear where it hit the valve, not very deep. Valve guide is toast, valve probably is , too. Found a tag on the side of the block that says remanufactered, and has a serial number, but doesn't say who did it. Also confirmed that it's a later model roller cam motor, and it's bored .040. So it's a 357 instead of a 350. Still have to get the other head off. Just gonna go ahead and get both worked at the same time just to be safe. Bro in law has a set of roller rockers I'm probably gonna get, and will be getting guide plates and probably some new pushrods, too. Not sure if the stockers are hardened for guideplate use or not. Maybe I'll get it back together before cruise season opens up....