I'd tend to agree w/BigEd36- Silvolite Pistons
, bottom of the page. Two possibilities are shown, one has a 0.070" deep dish, the other a 0.080" dish. Both are available 0.060" over. The numbers shows up under "O.E. Casting No."
If these are original pistons, they should have a CH of 1.56". But if they're aftermarket replacements, they're prollably going to be the shorter rebuilder type.