Going to .060" over is pushing things a little. I'd very much prefer .040 over if that's an option. Definitely consider sleeving #1 if it's got more taper wear than the other cylinders, even if you only go with the thinwall 3/32" sleeve. One sneaky trick is to use 307 V8 pistons- - - -they're flattops instead of the 1/4" dish top that the 250 piston has, and every other dimension is the same, bore size, compression height, wrist pin diameter and weight. I've also milled the head on a 250 engine .050" without having any piston/valve interference problems. With the flattop pistons and a milled head, the engine really comes alive.
Jerry
Hey Hotrod, all this modification stuff is off topic. And besides that you are polluting my mind with ideas of pursuing new avenues of adventure,for which I have neither the time nor the funds.
Carl
