A 60 overbore on a block isn't wonderful, but stovebolt engines have enough cylinder wall thickness to function with 60 or even 80 thousandths oversize cylinders. The main problem with a big bore block is it limits how many more overhauls the engine can tolerate. Since most of the oldtimers we deal with aren't going to be daily drivers, using a big bore block isn't as much of a concern as it might have been 40 years ago. Just be sure the cooling system and the engine's water jacket is very clean, as big overbores are a little more prone to running hot due to thinner cylinder walls.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!