So your plan is to make flat tops from the non chamfered ones? Everything you take off will reduce compression if you don't push the piston farther up the hole or bring the deck down. Custom rods? I don't Know it there is .070" On the deck. Another thing is that all replacement over size pistons I've measured have a shorter deck height than stock. When oversize pistons are made the pin height in raised to drop the bigger piston to maintain the stock compression ratio. So they are already a few thousandths shorter.
In the "old days" they screwed plates to the top of the piston to raise compression. Of course it was still low compression by our standards, rpm rarely reached 2,500, and they often didn't last long.
