[Walt Fricke]

You don't want to use J&E pistions unless you are switching to carbs or EFI. The CIS needs the funny shaped dome for swirling the air/fuel mixture. No aftermarket company makes a piston like that.

Good news is that you ought to get a decent used stock piston pretty inexpensively. Think of all those guys who switched to carbs and bought J&Es. Just have to match it up with what you have, and be sure you get the flavor you have: Alusil or Nikasil.

And, of course, figure out why this happened, and on just that one piston, too. Bad injector?