A friend has some Venolia pistons that are "supposed" to be for a Mopar Big Block 400 to 451 Stroker Engine?

They are Flat tops with valve reliefs that look like they are in the correct place, 4.375" bore, 0.990" pin, and 1.328" compression height.
The Top Ring is a 0.031" Dykes style, 1/16" second ring, and 3/16" oil ring.

Was this a piston someplace normally stocked, or a custom piston?
He has four (2 pairs) that appear to be brand new, and four others that are used, but the other four are not pairs, have 3 of one type valve relief pattern and only one with the opposite valve pattern.

Pics would really help, id say it could easily be either way on weather it was a shelf or a cut piston.

Id start by looking on the underside at what they started with to see if they all match and also use that info.

Call Venolia and ask them :scope
I'll bet any piston they make with a .031 dykes is a custom set
Does he have five lefts or five rights?