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1965 Engine Date Code.


Dean B

I am thinking of purchasing a ground up restoration of a 65 coupe and have a question on the date codes. The car is a June production car but the date code on the block is April (D55). Is this possible having the block manufactured two months prior to the the production date of the car?

NCRS accepts up to 6 months prior to build date of the car. Although 2 to 8 weeks is more common. Sometimes blocks were pulled from the engine line for repair or other reasons and were put back on the line some time after the repair was made. An example would be if a tap were broken off during machining there is no time to mess with it on the line. It would be repaired at their convenience at a later date and put back in line.


P. S. Welcome to the Corvette Action Center
1965 Date Code

Thanks for the quick reply. I think I'll buy the car!
Can't waite to see the pictures Dean.

Date Codes

There are some other dates you may want to check. Transmission, intake, differential and many others. If the owner will let you pull the valve covers there is a casting date on the heads. As Tom has stated, NCRS reconizes up to 6 month prebuild date for parts. The correct parts are very expensive and hard to find.

Good luck and Have Fun!

Addition: I re-checked my block code and I believe the assembly date for the 65 block is where you should be looking (5114957 F0405HE the F is for Flint, 04 is the month of April, 05 is the day, and HE is for the 250HP Corvette block). This will also tie your vin no. to the block. The stamp is located on the front left side(passenger) of the block next to the water pump. If you check my web page you can see the block code on my 250HP block. If you send me the total code I will ckeck the NCRS restoration guide and other resources and verify the numbers for you.


picture page
Date Codes

OK, Here we go:
VIN 194375S120723
Block Casting 3782870
Block Date Code D55
Pad Number on Block 5120723 F0609HU (350 H.P. with Air)
Carb R2818A 3849804
Alternator 1100694 5D12
Color Code: UU Rally Red
Trim: 444 Red&White Leather
Read End:AN
Intake 3844461
Exh. Manifolds: 3846563 Left 3797942 Right
Expansion Tank 65D
Radiator 65E
Teak Wheel & Telescopic
Power Brakes
Power Steering
Power Windows
Glass is JJ

Thanks for your help.I really like this color because of the color combo.
Date Code

P.S. The "D55" code I was referring to is located on the passanger side in front of the bell housing on top.
Date Code

Looks Very good, but John is the expert, and I am still learning! Your oiginal question was the time lag from the casting date to the car build date. I find it interesting to see the April 5 block casting date and the engine assembly date of June 9th. . two months, well with-in the six month NCRS window. It would be interesting to see other postings with build dates and casting date marks to establish an accurate time line.

Thanks for your post!

Good luck with your purchase!
A two-month lag from engine date to car assembly date is clearly not the "norm", but is acceptable under NCRS judging criteria; the "norm" is usually 4 to 10 days, depending on inventory conditions, holidays, strikes, etc. If the "norm" was the accepted "window" of acceptability, there would be far fewer NCRS members and far fewer cars being Flight judged - after all, these cars are 30-50 years old, were bought to be thrashed and put away wet by (in most cases) a long chain of owners, and how many "original" engines are really left under those conditions? That's why 525 points are assigned to the block casting number and casting date, and only 88 to the stamp pad.
NCRS Points

Hi! John
Could you please explain the NCRS point system for the engine.

Thanks Ray
The judging process for the basic engine block is progressive in nature; it starts with the block configuration and casting number - if incorrect, 350 points are deducted and engine judging stops. Next is the casting date - if correct and within 6 months of car build date, OK - if not, 175 points are deducted and engine judging stops. Next is the stamp pad - for pre-1960 cars (which don't have a VIN derivative), the pad is judged for the correct engine plant assembly date and suffix code stamp; if incorrect, 50 points are deducted. For post-1960 cars, points are evenly split between the engine plant stamp and the assembly plant-stamped VIN derivative - if either is incorrect, 25 points are deducted (or 50 points if both are incorrect). Last is the pad itself - if paint, dirt, or rust obscures the pad, or if the factory longitudinal broach marks are not present, 38 points are deducted. NCRS judging starts every car with 4500 points, and deductions are made from there, and the final raw score is divdided by 4500 to generate a percentage score. A Top Flight Award requires a minimum 94% score, or a maximum of 270 raw points deducted for the entire car (and the other areas judged, other than the basic engine block, are assigned 3887 points), so it's not possible to get Top Flight with the wrong casting number engine block.

Thanks for your information. One more issue just to be sure I'm thinking correctly. The pad reads F0609HU. I assume this means Flint plant and assembled June 9th and this is a 350 HP air car without TI. The body date below the glove box on the paint and trim tag is K14. I have been told this represents June 14th for a 1965 car. Does all of this sound correct? Would the engine have been assembled June 9th and shipped to St. Louis for a final assembly date and roll out of the car on June 14?

Also, I noticed this car sits about 1 1/2 inches lower on the drivers side both front and rear. Again, this was a body off restoration and it appears the correct mounts were used all the way around. Could it be the springs? Do they still make "doughnuts" that could be slipped between the coils and the a-arm? Would this affect NCRS judging?
1965 Engine Codes

Engine date code: F0609HU

F Flint
06 June
09 Day
HU 327 CI, L79, 350HP, Holley Carb., Hyd Lifters, 4-speed with air conditioning.

The Trim Tag K is for June, and 14 is day.

You may want to check out the NCRS site, they have a birthday section for Corvettes. Type in the vehicle identification number, and it will provide the build date or cars Birthday.

I will leave the technical questions to the NCRS experts. I would suggest you purchase a 1965 Corvette, Technical, Informational Manual, & Judging Guide. This will help provide the information needed to restore or replace parts on your 1965 Corvette.

Hope this helps:
The June 9th engine assembly date works fine with a June 14th body build date. The unequal ride height is most likely the result of spring sag. If you have the Assembly Instruction Manual, the front and rear ride height dimensions (which are independent of tire size) and how to measure them are shown at the end of UPC3 and UPC4. Spring replacement can be somewhat problematical and trial-and-error, as both the front and rear GM springs were discontinued years ago, and the reproductions tend to vary quite a bit in rate and ride height.

If rubber "donuts" are used to compensate for spring sag at the front, they should be installed at the top of the spring so they are not visible in judging. Anything you do at the rear is quite visible; check the condition of the rubber bushings where the link bolts from the rear spring ends attach to the rear of the trailing arms for deterioration. The rear ride height can be juggled somewhat by using longer or shorter link bolts.
Date codes

Thanks. Everything under the car is new as this is a body off, but not sure about springs.
other casting dates

Noland Adams book " Restoration Guide Vol # 2 63-67 " has the following dates and castings for the following vin #'s

Vin # Cast date assembly date

18648 E195 F0520HF

19357 E155 F0518HE

19597 E215 F0526HE

19830 F 45 F0608HH

The above shows that casting dates were three (3 ) to five days prior to assembly dates in May and June when your car was built. Also, I do not see any April cast blocks in the 20000+ vin area.

My guess is that it is a beautifully restored car back as far as the restorer could do at the time. The engine block probably was restored and restamped correctly within NCRS guidelines.

As John says, 37 years later it is a wonder any of these cars are still running. My first Corvette was a 65 fuel coupe that I bought in 1969 for $3500. The engine had already been changed but everthing else was there. I sold it in 1974, wrong motor and all for $4500........and nobody cared about "matching numbers"
Save the Wave,
ngine Codes

Thanks to each and every one of you for your responses. I've been in New Orleans at Marti Gras and have just returned. I am still negotiating on price. The car is perfect in every way...Now the question to those of you that have kept up with the market. Is it worth 40 grand considering the options I have mentioned. I have kind of lost touch.
$$$ Value??

Without seeing the car Dean, hard to say. The things that bother me are the spring sag issue...........It is a coupe.......and the engine time lag between casting date and assembly date stamping.

Does the car run and drive correctly? Does the AC blow cold? Can you pull 4500-5000RPM out of the motor with no smoke or crazy noises? Does it steer and stop correctly? Has the car ever been judged NCRS? How did it score?

I realize to do a body off would cost $40000 + today and then add the value of the car you are restoring. If you really like it, buy it!! But I personally think you are paying top $ for a car that needs to be looked at by an expert. I would be happier if you could get into the car in the mid $30's.......but the market is very strong now and 350hp AC convertibles are in the high $40...low $50's. So a nice like equiptment coupe should sell about $5000 less. Coupes have always been less. Why I do not know as personally I like them better. But the public bought 65% convertible and 35% coupe when they were new, and the same holds true today.

Hire a professional to look at the car. Don't let your little head do the thinking. Make sure there are no "hidden" secrets about the car. If it is right the seller will be proud to tell you so. Good luck.
Date Codes

Thanks for your response..I'm going to have our local NCRS folks take a look. It has not been judged but with the information I have read, the car is pretty much right. It drives like a dream and no problems pulling 5600 rpm's. Someone has told me if the front coils are not installed properly and seated in the lower a-arm correctly, it can change the riding heigth. Also, where the nut attaches to the trailing arm bolt, if not installed and pinned in the same position on both sides, can affect the height. I'll check this. Thanks!

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