Date decipher on cast iron thermostat housing

[Garry B.]

Re: Date decipher on cast iron thermostat housing

Thanks Joe. I have always considered you to be the subject matter expert on all corvette questions / answers. This whole thing started when i noticed this housing on my very original '64 and naturally thought it was a February '63 part which would clearly not be correct. Everything points to it being original with the exception of this set of B3 stamps. All good now and thanks for your input.

[Kenneth B.]

Re: Date decipher on cast iron thermostat housing

Kenneth------


I think so, too. I don't think these housings were cast at a GM foundry. I think they were out-sourced to some independent foundry. The "GM" and "3827369" were part of the GM specifications for the part. The drawing probably also required a manufacturer's ID mark and that's likely what the "B" is. As many have opined, the numeral following the letter is very likely a pattern number emplaced by the foundry for their quality control purposes. This part is a sand casting and a pattern is used to make the sand mold.

JOE
yes a lot of small simple parts were sourced to other foundries. We made many patterns for GM that were cast at many other foundries. Some "B" foundries were Bremen & Bridgewater that made iron castings for automotive parts.

[John D.]

Re: Date decipher on cast iron thermostat housing

I believe John Hinckley etal told us long ago that the B3, B4, B5 etc that I have seen on the 370 waterlets is NOT a date code but just as a lot of you said above. Mold info.
Also not all of those 370 outlets have a B number on them. John

[Joe L.]

Re: Date decipher on cast iron thermostat housing

Also not all of those 370 outlets have a B number on them. John

John------

Probably because those were cast at a different foundry, perhaps even a GM foundry. I don't think that GM foundries were required to place foundry identification marks on castings although they often did. Tonawanda and Danville, IL were usually good about including foundry identification marks; Saginaw and Defiance, OH, not so good about it.