Engine Question

I agree with both above. There should be a part number stamped somewhere on the piston face, side, or underside. Interweb search. Choosing another piston is bad for balance as mentioned and potentially compression. Agree to rebalance etc. I ran into the need for this same thing once on a dropped valve and lucked out the Mahle sold my piston in a 1-8 quantity instead of by the set of 8.