Pulled the head off one side and this is on the top of the piston
L22 oo 060
(SBC flat tops with 4 valve reliefs.)
I tried to google it but it seems to pull in every 60 over piston made. I am trying to find out the brand and if they are cast or forged, I assume 060 means .060 over. So I guess that makes it a 358 or somthing.