Yeah. I saw that page as well as others. I also referenced that prefix in and old repair manual my pap gave me and all show say 1951.
I believe the numbers are 661215. But it actually looks like 66I2I5. The "1's" look like capital "i's"
I'm a little concerned.
Oh...I also need a lead on a rebuild/overhaul kit for a 216. Can anyone point me in the right direction please. ( just a complete gasket kit)