trying to identify aftermarket 340 Pistons

I’m aw
If the motor had that many issues, I would suggest having the block checked out first to be sure your bores are still true and .030 replacements can be used. Nothing worse than assuming and then having it all go wrong.
Im aware, the cylinders don’t look that bad surprisingly, just a little scuffing. it had very low miles on the rebore. the cam and bearing damage were all caused by my stupid mistakes. I unknowingly dropped the coil terminal nut in the distributor hole when switching to electronic ignition and it fell into the cam and chewed up a lobe. years later i bought a new cam , tore it apart cleaned it out the best i could and put in new oil pump . at that point the bearings were good no signs of wear. when i fired it up oil pressure was at at 80 psi for couple seconds and then dropped to 10 and stayed at 10 . I took the engine back apart and the oil pickup was loose and the bearings were scored.