The Stovebolt Site Forums The Shop Area Engine Shop Block number deciphering

I have what I believe is a 235 cu in inline 6 from my ‘50 3100. There was a scrap of paper in the glovebox that indicated it was a transplant from a later model passenger car. I have looked around on the site, and haven’t been able to decipher my numbers.
They are CON3 E269 and then the forward numbers are 8764476. Can anyone decipher these and confirm what I have?

Paul, Based on just the info you provided, I think your "8764476" should actually read "3764476". "3764476" is the block casting number listed for multiple vehicle applications (see 1st pic). The "CON3 E269" is the blocks date casting code, which decodes to E = May - 26 = 26th day pf the month - 9 = 1959 model year.

Further confirmation can be added if you post the Serial Number stamped on the machined pad just to the rear of the distributor on the block. You may need to do some significant cleaning/scrubbing to get to it.

That stamping appears to be HBA362728

Paul, That serial number beginning with HBA would indicate it as a 1950 216 according to the GM Heritage site. As the letters and numbers stamped are not the same style/font size, best guess is the engine is most likely a dealer sold replacement that was stamped to match the trucks original engine serial number. A common practice from other posts on the subject throughout Stovebolt. Others will probably chime in to provide more details on this.

But the casting numbers on the block say it’s from 1959. To say I’m confused would be an understatement.

Would they have stamped a 235 as a 216 because that’s what the truck was delivered with? Or is what I have actually a 216?

What Dan said about replacement engines being restamped with the original serial number. Pretty common occurrence if the vehicle was registered with the engine serial number instead of the body tag number (VIN in later years,) I have a 1953 casting number 216 engine with NO serial number on it in my 1951, but have documentation that it was installed in the truck in 1954 by the government agency that owned the truck then. I also have a 1958 235 engine per casting number with a serial number indicating it being a 1955 engine. That one was likely installed in a 1955 truck as a replacement, as there were no time machines back then to get a 1958 engine to put in a brand new 1955 vehicle.

Ok, thank you for clearing up my confusion. Thank God vehicles are registered now with the VIN, not motor serial numbers.

Would they have stamped a 235 as a 216 because that’s what the truck was delivered with? Or is what I have actually a 216?

1953 was the last year of production for the 216. Based on the casting number it has to be a 235.

They stamped the replacement engine with the original engine serial number because more than likely that's what's on the title. Using the engine serial number on titles was common before 1955.

Mike B

Thank you all for clarification. I appreciate everyone’s help.