I just got off the phone with my machine shop. The boss wasn't in but his second in command said he thought Sealed Power or Silvolite still had a piston for that application in cast or hypereutectic. They build a lot of marine flathead engines and that's what they use for most of them. Lots of Continental and Hercules as well as Chrysler.

Egge as a last resort if nobody else has one. Nasty rough looking and $$$$.

Kevin