Hey guys I have 2 c3's that I am building and wanted to get some advice about date codes. One of the cars is a 73 454/4spd car that aside from the motor is all original and in incredible shape. I am restoring it and I would like to put a date-correct motor in there since I assume the original is long gone. I came across a 454 out of a 1 ton truck that has the same casting on the block as the original (3999289) with a date code of A 26 73 (January 26 1973) and the correct casting of the heads (353049) but with a October 25 1972 date code. Was it common for something like this to occur since they time frame is very close or was it likely the heads were changed? Also, where could I check on my car to find out what the correct date could SHOULD be? I found this motor for an amazing price so if this is what I'm looking for I would like to scoop it up ASAP

 

What's the Time Built code on your trim tag? That date tells you the day your car passed the station on the line where the trim tag was attached.

Back up about three weeks from the Time Built date, possibly longer, and you will be getting in the neighborhood of when the original engine might have been assembled at Tonawanda.

Next question: since the engine is not going to be original for you car, why fret over the engine assembly date?

It is not uncommon for heads and manifolds to have different casting dates than blocks.

 

I wasn't sure if I should be worried about it or not, hence my thread lol. The tag on the inside of my driver door says 06/1973 so should I assume that this motor "could" have been produced in a time frame that it "could" have ended up in my car?

 

You may be reading the vehicle certification label on the door instead of the trim tag pop riveted to the driver's hinge post. June 1973 does not give you a day. The Time Built code gives you a date and is in the upper right corner of the trim tag. Look for Kxx. K indicates June; the xx would be the day of the month.

Everything on your must must have a date earlier than Kxx since all the parts for your car including the engine were already on hand at St. Louis before assembly of your car began.

Engines could have been assembled any time within two weeks or more prior to Kxx. Block casting dates would be older than the engine assembly date anywhere from a month to a year prior to the engine assembly date.

An engine block cast in January 1973 might be okay for you, although dates were often closed to the production date of the car.

Here's a sample time line:

Block cast May 29, 1973. Casting date could be earlier.
Engine assembly date June 5 (T0605xxx stamped on the engine pad)
Time Built date on trim tag K21 (June 21, 1973)

Between June 5 and June 21, the engine for this car was shipped from Tonawanda to St. Louis; received at St. Louis; and stockpiled. It was on hand on June 21 when the trim tag was attached to the car.

 

Okay so really I should be looking for the assembly date of the block rather than the casting date?

Also, not that it matters, but I was looking at the inside sticker. The trim tag says K04 (which made me laugh a little since I've dealt with a lot of K04 turbo cars over the years)

EDIT: looks like the assembly info is T 02 15 TRK which tells me it's the correct plant on Feb 15. I assume TRK stands for truck?

 

June 4th

A February built engine for a June built Corvette is a stretch. An early to mid May engine assembly date would be ideal.

 

Beautiful thanks so much for the help

 

My car is July 8 on trim tag, Engine assembly date: May 27, block cast: May21, Heads cast April 27. Reading the NCRS judging manual they seem to accept up to six months prior to trim tag date as acceptable.

 

Really? Interesting. That makes my search a bit easier

 

What model year?

Correct. The NCRS attempts to take into consideration assembly line anomalies. Actual production dates were usually closer. Keep in mind, a myriad of parts were stock piled at St. Louis.

I consider my 68 to be typical. Block cast 4/4/68. Engine assembled 4/9/68. Time built code 4/20/68. NCRS shipping data report says the car rolled off the assembly line on 4/22/68.

I have one head cast at the end of March and one at the beginning of April. Offhand, I can recall the casting date of the intake manifold, but I've got it jotted down somewhere.

 

1970

 

July was the final month of 1970 production. In a typical model year run, your May dates would likely indicate a car to be assembled in June, but 1970 was not a typical model year run. They were busy in St. Louis during that July. Nearly 3500 cars were assembled.