Aaron,
It was great to bs w/you at the Nats. We're already getting ready for French Lick. Ha!
The O-ring you are looking for, assuming you are referring to the 232-262-308 Family, is a 3/4 X 1/8 (ID X Cross section per std o-ring nomenclature).
The Parker # is 2-210 (industry std 210) and should be no harder than a 70 Durometer to conform to the relatively crude finish on the Hudson pan and block. The local auto parts store probably won't have any idea what you are talking about so look for a 3/4 ID X 1 inch OD. Be careful of what you find in the bin...they're probably all mixed up. :pinch:
If you are looking for a seal for the '39 to '52 splashers, I'll find that one, too. Not sure about others.
Frank

I found one that was 3/32 thick. Anyone have experience with one that thick.

Frank, do you think that is enough rubber?

Aaron,
You meant, "one that thin", right?
The chamfer in the block represents a pretty large void to fill and I wouldn't use anything less than the 1/8 cross-section ring. A leak at that point could be disastrous since it is in the inlet circuit to the oil pump and operates at less than atmospheric pressures, allowing the rest of the world to push air into the inlet tube. The slightest air leak could prevent the pump from inhaling oil or it could result in aerated oil (foaming). Aerated oil doesn't lubricate as well. It's too important to leave to chance.
Are we talking about a late, pressure lubed six (not Jet, it's different) or some other engine?
Frank

Frank

I have a 39 with the 212 splasher six. Can you help with the seal for that one?
Vic

Vic,
The '39 212 (and all) uses an O-ring with a 1/2 inch ID and a 3/32 cross-section. Industry std nomenclature would call it a 1/2 X 3/32 but the parts guys would likely say 1/2 X 11/16. I don't see any O-ring spec'd for pre '39 implying that they relied solely upon the pan/tray gaskets to seal those interfaces. According to the books, '39 was the first year of O-ring use. Not surprising, since I don't imagine O-rings were in common use in [i]anything[/i] prior to those days, as the technology didn't exist. Hmmmmmm. I guess I should read up on the history of the O-ring.
Frank