Budget 318 build

Yep, the 318 is tougher to do as there are not as many piston options. Got that Sealed Power number handy? If it is 814, then teh FM catalog does list them as 1.755" CH, and you might get them on eBay. They don't come up as regular sold items from distributors anymore. BTW, watch the valve to piston clearance with a higher lift cam on those flat tops; see a recent thread on the bent pushrods.

BTW, here is a link to the Silvolite catalog; if you look at their listings, you will see similar specs and also see the Federal Mogul/Sealed Power equivalent PN's (like 526 and 814) and so be able to get the Silvolite equivalents.
https://www.uempistons.com/catalogs/silvolite_catalog.pdf

Milling the block by .060" is a bunch, but seems plausible. I bet someone can advise you how much you can mill safely, and your shop might know. You ought to call them and see the costs: more data. As you mill the heads and block keep in mind that the pushrod lengths will have to change. And boring .010" is unusual.... see what they say and if you can even get .010" oversize. .020" or .030" oversize would be more normal. Being able to clean up the taper with a .010" overbore is sometimes problematic.

BTW, why not do the 360 again? More damaged?