Did they Sonic test that area? A machinist friend honed a block one time and the bores wouldn't stay round. Upon closer inspection he noticed a couple of holes in the area he was having trouble with. He put the sonic tester onto it and it was paper thin, so much so that with a tap with a screwdriver, it went through the cylinder wall.

It could be a hole in the casting and nothing a sleeve won't fix, I had a Hemi six that had the same problem. Ran fine for years.
AL...