^^^ that's what I'd consider, going 30 over & locating a single piston & I believe OS sets are lightened to keep the balance factor the same (or close) as std pistons & if it is heavier (& crosses the line to where it needs balancing adjusting) you can trim the pin as BB pins have more contact area than needed & can easily lose 1/4 off of each end with no compromise to durability. HF has a gram scale for $9.99 or likely get one for free with the coupon with another purchase & they always have SOMETHING that you cant live without!
His block is already .060" over.
Depends on how loose the one hole is.
The options are run it or have that piston coated or knurled if it's too sloppy or go with a set of standard 440 pistons. Without an actual measurement there's really no way to give a good recommendation.
If this was a running engine at .060" over and it didn't crack, I don't think I would lose any sleep over an extra .005" on the radius if the easiest solution was a set of standard 440 pistons.
Kevin
