Found a set of Arias A12 pistons digging through the parts. I believe they are standard bore but I need to check one more time. I wish I could tell the exact compression on it, but the side of the box just has MAX written where the c/r should be so I guess just mill these to your desired compression ratio. I believe there are also rings and c-clips for the wrist pins so this will require fully bushed rods.

These are not for the faint of heart, big power a12's need these.

Parts are located in USA and might consider international shipping if they sell for the right price.

I'd post an asking price but I have absolutely no idea what something like this is worth, atleast for an a12.

sounds like an old set of datsun comp pistons
they sold pistons from several manufactures over the years