Run into two engines so far that the valve guide moves out of the head as it is running. Goes so far then bends push rod , it flies out and bends intake rod. Another local shop has seen one too. I staked the guide around it's base and told customer if it came out again need new head. Anyone else seen this, Restorob? Clean around the fins so not a localized heat problem but has got to be something, maybe tolerances got a little loose at factory? One head was priced @ 85$ other @ 140$ valve guides at machine shop about half that?