Julian Date Confusion, Please help.

[robota]

I need verification of a date code on a 1964 409/340 Block. I have it in a real fine 4 spd 1964 SS with a lot of paperwork tying motor and trans to the car.

The front pad is what it should be, with correct Vin and a date engine build code of 9/17. The mill and stamping look correct. It is a Tonawanda build with the correct QC suffix.

The block casting # makes sense and is: 3844422. It has a clock code below to the right of the casting #. My cars body build date is the 4th week of Sept. The car was delivered to the dealer in Oct 63. All cool so far.

The date code on the pass side trans flange is the Julian code of 108. (April 17th) Both of my heads are the correct casting #and have Julian dating of 108, and 92.
The heads are CFD marked.

This is where my confusion comes in.

Questions:

With my Julian coded parts, does it mean that they were cast in April of 1963? Is that possible with an engine build of 9/17/63 and a body build in the 4th week of Sept.? Or does it mean that it had to be cast in April of 64? (Ruining my day completely). Does the Julian calender on an early car make sense?

Colvins book does not even mention Julian coding on motors, and also says if it is a Tonawanda build, that the parts would have to be cast at Tonawanda.

Also, in Colvin's 60-64 book, he makes reference that just the Saginaw blocks had clock codes, or did all of the blocks have them? Being that this motor is a Tonawanda build, is it possible that this block was cast elsewhere, (The heads definatley were) and then shipped to Tonawanda?


I know its a mouthful but I am soooo confused and could really use your expertise. Thanks for your time.

[Ronnie Russell]

robota, I may be wrong, but a #422 block with Julian code of 108 would have been cast in 1964. Don't see how it could go into a car with a late Sept (63) assembly date. Maybe others have a better explaination. I may be over looking something. If I am correct, I'm afraid the block is re-stamped. Hope I am wrong.

[1958 delivery]

Sounds like a possible matching engine, just not in that car.

[Ronnie Russell]

It would have been a matching number engine IF they had not stamped the block deck. That blew the whole deal. :doh :doh

[robota]

Isn't it possible that an early model year '64 could have a left over late 63 block?
(Colvin alludes to the 422 block as being possibly used in '63.)

[Ronnie Russell]

robota, One of our members does have a 63 (July) with a 422 but this has nothing to do with your problem. Your problem is the 108 date. No way to get around the April casting date. A left over late 63 block would have a corresponding Julian date . Just cant get away from the 108 date on your block. Sorry................

[robota]

I'd love to know the casting date of the member with the 442 block in his '63. Just to see how far back they made the 422.

I have a good trace on the history of my car and have talked to all the owners. Of course this is very upsetting to me, but knowing what I know about the history of the car, and knowing the mill lines and stamp are correct looking I feel there is a chance the block could be from 63.

I know it is not the norm, but some cars are known to have longer than the 3 month stretch from cast to assembly. Probaly not possible to be sure though.

Damn the Julian system.

[1958 delivery]

Broaching the block correctly during a re-stamp has been around a long time. Window stickers, new cowl tags, vin tags, build sheets and protecto plates have been "reproduced" for some time now. It sounds like you're confident it's a real 409 car, probably is. It just doesn't have the orig engine in it.
Some one did right by putting a "period correct" engine in it. Look at it this way, you can continue to look for that correct dated block out there, somewhere.
By the way it's also possible to "change" the date into the correct one. There are very talented people out there.

[robota]

Well thanks, I would never fake a thing, and am very happy to inform, that I don't think i'd ever have to.

I have just recieved some wonderful info from a member here that blows this whole thing to bits, and sets my mind at ease. His late 63 production 422 block was dated julian April 1st. It was installed at the very tail of the 63 run on July 03. He is sure of the originality of his block and car.

It only stands to reason that my 422 block dated julian April 17, could have obviously been left over from the 63 run and installed in my early production car. Consider my heads are dated the same time as the block and you come up with a more convincing than not argument that it is correct. Remember julian dating was to move older product first, kind of a rotation of the shelves deal. The year date, did not matter to guys that might as well been making paper cups. Add to that that we don' t know how many blocks were made in 63 and left over for 64.

If this motor was replaced and the block was restamped, chances are good that it would have heads that were not so closely matched I think. There is really no way to absolutley sure, (besides being the orig owner) and opinions can differ, but what is sure is there is NO absolute when it comes to production and dating. With what I know about the originality of my car, the converstions with previous owners, I think the 3 month rule, at least in this case - has been trashed.
Yeee haaaa.:beerbang

[1958 delivery]

[QUOTE=robota;67063]Well thanks, I would never fake a thing, and am very happy to inform, that I don't think i'd ever have to.



I wasn't implying that you should alter your numbers, I was pointing out that this is routinely done, and many people know how to do it.


So considering your block was cast in 1963 then it sat somewhere for 5 months before it was put in a production line car. I guess it's possible but not a common thing. Most cars have engines that were cast within a very short time of the build date. 2 to 4 seems to be the norm.

[robota]

You have to remember the changeover from the 63 model year, which ran ( per a members example) at least a little long into July, to the 64 year. That leaves a month where none of the 422 blocks went into any cars. That cuts down my time from cast to install to 4 months predated. And who knows how many of the "new" 422 blocks were made and stockpiled? I know 1 to 4 months is sort of the norm, but considering the year changeover, and that quite possibly there was a healthy run of the new 422 block (It is cost effective to do so), it is highly likely this block was used in an early '64 assembly.

In Colvin's book a quote I just read on model years goes like this:

"... note that for a car built early in a model year, many parts correct for that car would be dated from the previous calendar year."

[Ronnie Russell]

Well I am sure now that I know nothing about date codes. We have robota with a 1964 340-409 that has a #422 block cast 4-17-63 , engine assembled 9-17-63 and car assembled 4th week of September 63. Jim G with a 1963 340-409 that has #422 block that was cast 4-1-63 and installed in car 2nd week of July. So I guess there are no #814 blocks cast after 3-31-63. Afterall. why would GM cast two seperate numbers at the same time. ?? Unless there were two seperate foundries casting 409 blocks at the same time. This stuff is way to confusing for me. I will putt on down the road in my 62 with a #422 block and not try to figure this correct stuff out anymore. :doh :doh

[robota]

Not to confuse anyone further... what I would love to know is if anyone out there has a 422 block with a NON JULIAN date code. I have a theory that Julian codes were done on the initial run of a part (maybe by certain foundries). Remember dating was a way to keep track of production and engineering changes. In assembly, it just made sense to use older parts first. (It wasn't like a block would explode if it reached the 3 month limit.)

It would be confusing (again a theory) if two years overlapped with Julian codes. So maybe the second (calender) year of the run, the julians were gone.(??)

This brings up the whole notion of Tonawanda casting everything they assembled.
I think with Jim G's car and mine we have found exceptions. Anyone have an opinion on this subject?

[chevymusclecars]

I have an QB engine with a 422 block and the Julian date is 284 which would certainly not be an early block no matter how you look at the numbers.

Bill

[robota]

What is your build date on the motor? Is it a 64 car?

[Brian64SS]

My '64's body VIN matches the VIN on the 409/340 block. I bought the car relatively cheap 15 years ago (before prices got crazy) so I have no reason to think the previous owner doctored it.

The body was assembled in St Louis 4th week of December 1963 and the block and heads are julian dated within days of JFK's assassination in late November 1963. So a lead time of one month. I'm not discounting any other theory on lead times or use of left over 1963 parts, just giving an example of what they were doing in St. Louis by the end of 1963.

[models916]

Off to the side til later is what happened to assembled engines on the line that needed some other attention. Fixed whatever the problem was when they got time and then put into use. I don't know how long they could have sat.

[Ronnie Russell]

gearhead, :rofl :rofl I'm with ya on that!!! I don't know nuttin' about nuttin' . That's my story and I'm stickin to it. :doh

[robota]

My intake is a 465. Strangley enough it has no date code that I can find.

[Jim G.]

I have a 63 with a build date of 2nd week of July with a 422 T0703QC block and a 3830831 intake (can't read date, too much paint).

Jim G.

[chevymusclecars]

I went out and looked at the engine, as I said before the Julian date is 284 and the engine is stamped T1111QB. If you believe Alan Colvin a block cast in 1963 will not have the Shift Clock on the back of the engine. This engine has the shift clock so I would guess it to be cast the 10th day of October 1964 and assembled the 11th day of November.

I removed this engine from a car that another member on this site now owns and no the engine was not original to the car so I commited no sin. The engine will probably be installed in my 63 Biscayne so I will have a car to drive to Norwalk that is powered by a 409.

Bill

[robota]

:stooges The crack up about Colvin's reference there is ... well here's the quote:

Sometime during the 1964 model year, a casting clock code was added to some Saginaw blocks, .........(he goes on to describe what it looks like and location, then incredibly adds); See block #3830814 below. (!!)

But again he does say MODEL year, not calendar.

This again opens up another hornets nest, as he also says on another page that Tonawanda assemblies used only their own castiings. WTF.:stooges

[oldskydog]

Here's a little more info from the 1946 to 1964 Parts Catalog :

0.033 Block Assembly, Cylinder

Partial Engine

62 Pass (409), 63-64 Pass w/H/Per., dual 4BC (409) (1st design) (exc. RPO
Z11).............................................. ........... 3839753 (cast 3844422) (Note 8)*

Note 8: Contains (1st design) camshaft 3830690

63-64 Pass. (409) (exc. H/Per., dual 4BC, RPO Z11)............3839755 (cast
3830814)

64 Pass. w/H/Per., dual 4BC (409) (2nd design)...................3865807 (cast
3844422)

Fitted Cylinder Block

62-64 Pass. w/H/Per., dual 4BC (409)...................................3839752 (cast
3844422)

63-64 Pass.(409) (exc. H/Per., dual 4BC)..............................3839754 (cast
3830814

0.269 Head Cylinder

61-64 Pass., w/H/Per., dual 4BC (409) (exc. RPO Z 11)........3852582 (ident. No.
3852583) (Note 8,9)

Note 8: Used only with camshaft 3830690, valve spring-3817277 and shim-3853875 on 1964 models with engine date stamps prior to T1118QA and T1118QB. Used only with camshaft 3837735 and valve spring- 3858367 on 1964 models with engine date stamps subsequent to T1118QA and T1118QB. It is necessary to use shim 3853875 on 61 to 63 models.

For further information refer to Chevrolet Service News Volume 36, No. 6, June, July 1964.

Note 9: Do not use on early design 1961 (409) engines.

0.519 Camshaft

61-62 Pass. (409),
63-64 Pass. w/H/Per. dual 4BC (409) (1st design) (exc. RPO Z
11................................................ ........................3830690 (Ident. No.
3822930) Use only on engines prior to T1118.

63 Sport Coupe (RPO Z 11),
64 Pass. w/H/Per. dual 4BC (409) (2nd design)............3837735 (Ident. No. 7736)
Use only with engines subsequent to T1118.

This catalog was printed in 1974 indicating that either 814 and 422 blocks were still being cast for service or there were left over blocks from production still available for service. Since the 656 block was the last production casting made which should be available for servuce and there is no mention of it in this catalog, it seems likely that these are left over blocks from 63-64.

Notes 8 and 9 above seem to establish the change over date of 11-18-63 for the Z 11 cam use in 64 production solid lifter engines requiring 583 heads with different valve springs.

Does anyone have the Chevrolet Service News issue from June/July 64? It should give more info on the engine changes.

This also seems to indicate that both the 814 and 422 blocks were used simultaneously at least during some production overlap. I recall an article by Curt Harvey in an old magazine article that indicated the 814 and 422 blocks were both used in 63 and 64.

:scratch :scratch :scratch