What's the bore size, standard or oversize? I've got a bunch of cast iron 216 pistons sitting around that I'm not likely to use on any of the engines I rebuild. I bore 216's 60 over and use aluminum 235 pistons in them. It keeps Babbit rods from wearing out in a hurry due to the lighter weight of the pistons.
While you're in there, consider installing a set of spring steel "piston skirt expanders". They really quiet the engine down by reducing piston slap, especially after a cylinder gets honed and ends up slightly oversize. There are several sets on Ebay right now, at around $20.00 a set.
Jerry