3 digit vs. 4 digit assembly date on engine pads

[Edward M.]

OK, as per a suggestion from another member, here is a separate thread on the topic of 3 digit vs. 4 digit assembly date codes.

1955 and 1956 265 cubic uinch engines did NOT have an assembly date stamped on the engine pad. These two years used an 7 digit sequence number (with leading zeros as needed).

The engine plant, engine assembly date, and engine suffix code as a combined engine pad stamp with the 1957 model year engines.

A 3 digit assembly date code was used for the months of January (I) to September (9), plus two digits for the day of the month.

The 3 digit engine assembly date was used for 1957 to 1959, and early 1960 engines.

It appears that 1960 model year engines that werr assembled in the 1959 calendar year (August, September) continued to use a single digit to represent the month. 1960 Corvette 00867S101189 has what appeasr tobe it's original engine. The engine stamp is F923CU.

I located two different 1960 Chevrolet engines with what "appear" to be original pads. Neither are Corvette engines. A January 15th assembly date for a Tonawanda 348 engine has a assembly date of T0II5FE. A January 22nd Flint engine has an assembly date of F0I22xx (can't make out the engine suffix code, the picture is too fuzzy).

So, we have a Sep 23, 1959 engine (for an early 1960 Corvette) that has F923CU (3 digit date code), and a January 22, 1960 engine that has F0I22xx (4 digit date code).

Thoughts?

[Dan A.]

Re: 3 digit vs. 4 digit assembly date on engine pads

From an EvilBay auction October 24, 2006. VIN 00867 is a 4 digit engine build date. Originality is unknown to me. Also the vin tag is on the steering column.

00867S104464stamppad.jpg00867S104464vin.jpg

[Dan A.]

Re: 3 digit vs. 4 digit assembly date on engine pads

VIN 00867S101189 currently at auction on EvilBay has a 3 digit engine build date. The vin tag is in the drivers forward door jam.

00867S101189vintag.jpg00867S101189stamp.jpg

[Dan A.]

Re: 3 digit vs. 4 digit assembly date on engine pads

The vin tag for 00867S101203 appears to be located in the door jam. This picture was taken from an evilBay auction July 31, 2006.

00867S101203vinrtfrtdamage.jpg

[Dan A.]

Re: 3 digit vs. 4 digit assembly date on engine pads

00867S101617 has a 4 digit engine build date. I saved this photo early March of 2009 but do not recall from where. I have no idea if it is an original stamp.

00867S101617 F1208CQ_jpg.JPG

[Jim D.]

Re: 3 digit vs. 4 digit assembly date on engine pads

So, we have a Sep 23, 1959 engine (for an early 1960 Corvette) that has F923CU (3 digit date code), and a January 22, 1960 engine that has F0I22xx (4 digit date code).

Thoughts?

From the pictures and info. I've collected over the years, I believe the change from single digit to double digit ( 1 vs. 01 for Jan.) was sometime between 1-12 and 1-18-1960. I have examples of F105xx, F107xx, F112xx and then F0118xx, F0120xx and F0126xx.

[Edward M.]

Re: 3 digit vs. 4 digit assembly date on engine pads

Another data point, which may be applicable, is a Tonawanda 348 engine with an asssembly date of T0II5FE (4 digit date code). No idea if there is a correlation of 3 to 4 digit assembly date code changes between Flint and Tonawanda.

[Edward M.]

Re: 3 digit vs. 4 digit assembly date on engine pads

Screws are definitely wrong, but it looks like an aluminum tag, which would be correct for an early 1960 with the VIN tag in the door jam area.

So, does anyone know of a car later that 1203 that has the VIN tag in the door jam?

[Edward M.]

Re: 3 digit vs. 4 digit assembly date on engine pads

OK, a couple more data points. Assuming these two engine pads are correct..

VIN # 3202 Engine pad stamped 103202 (individually stamped digits) FI05CS (3 digit date code, January 5th, 315 hp FI engine)

VIN # 3316 Engine pad stamped 103316 (appear to be in a gang holder), F0122CT ( 4 digit date code, January 22nd, 245 hp 2x4 engine)

[Jim D.]

Re: 3 digit vs. 4 digit assembly date on engine pads

My bet is 3316 is a re-stamp by someone that doesn't know what they're doing due to uniform stamping and the reduced size of the VIN stamping. I have many examples of original pads up to and including 5874 that all have the VIN stamped free-hand and in the same size as the assembly code. At a recent show, I pointed this info. out to someone that had a similar pad that swore it was the original engine, gang holder and smaller font, and after a little conversation, they admitted it was a re-stamp by a "restoration company".