Piston piece

I'll try again in the Am; unknown engine; original 70 pistons, I think. Castings say 70 340 block, Pistons are out of the bore in places, Like 1/3 with a little dome, is out..17" . Valve reliefs cut in. I can't remember if this was stock 10.25. No ridge, and the bores have a chamfer, right at the top 1/8".
Double notches to the front. 2.02 j heads. And the unknown cam that wants 30 degrees at idle.