QUOTE(Mikey914 @ Aug 25 2023, 07:02 AM)
Size is ok, add additional oil capacity with an offset cooler and a temp gage. I wouldnt go any bigger, but its managable.
Replace the head and drive.
Don't think it just as easy as bolting on another head,expect you need to get FAT to make another one up to match the other side ,numbers on the head would indicate specs I would say ?.
Then there is the question of how long will the remaining head hold up if the combustion floors are really thin as the OP mentioned ?.
Perhaps a reduction in CR may make them last longer but don't know in this case .
The effected cyl looks to have been running lean but hard to say if that was caused by the hole or detonation previously.
Remember back when I bought a set of heads off a well known builder in my country and needed them flycut for compression increase and he mentioned you can't cut then too deep with the big cylinders but with mine that was not an issue.
Don't think the solution is that straight forward.