Piston Identification

I have 427 tall deck that I haven't taken apart yet. Motor may have been rebuilt not long ago. Pistons are clean in the bore. I didn't have my measurement stuff to measure the bore. Pistons have single valve relief and part number Z16 and 46 below on the piston center. Can anyone identify what piston this is by the number? Thanks for any help.

 

There should be a name someplace under the piston . If it's a overbore it will have the size stamped on the top .