CRS bolts into cast aluminum is the newest problem, 71 inch-pounds of torque on those camshaft cover bolts is about the maximum. If electrolysis occurs, the threads of the aluminum will come out with the bolts, sounds like somebody got carried away with excess torque.
One repair is to just replace the head. $$$$! Another is to go to the next largest size bolt, whether it be metric or English, latter call those SAE bolts now, even though they didn't have anything to do with units of measurement. Run into this quite frequently, brings back memories of working on 30's car. Knew how to make bolts back then, major problem was breaking the wrench instead of the bolt.
Those couple of bolts could be tapped to the next largest size, and to increase the clearance holes the same amount. Or you could fight to get a new head.
Just another more recent change, goodbye gaskets, hello RTV. Very happy that all my drills and taps were made in the USA. If you tried this with this crap from China, would be helpless.