Topic: Number Matching - Engine Casting Dates

[dearbornshow1968]

For once and for all ??  What is the acceptable date range between parts including drive train to the build date of the car itself . What is considered matching Numbers ?

[67gtasanjose]

It really varies a whole lot depending exact build date on any given vehicle. There is no "for once and for all" answer. Look at it from the standpoint of supply and demand and also consider destination vs. a given manufacturer's assembly plant location (say on engines) If an engine is built in Windsor or Cleveland and car is assembled in Dearborn...not a far trip on a rail or truckload. Just a few days between. Going to N.J. or San Jose might take a week or two (per-say) If it were a lower volume build, such as a K-code or S code, those might have a longer time in the hold (though not by much) Look at the final assembly date on the block and consider that the individual parts going into the completed assembly are going to be dated before that date...things like that is where the numbers need to match closest. It's a real challenge at times to match these all up perfectly to a car that no longer has many of it's original pieces. Not impossible, but challenging. Do research on all original cars built like yours in options & nearest to yours (usually within a week) for the build date. That will dial you in the most accurate way possible.

[tim_morrison82]

and dont forget to take into account strikes, etc, especially if your car is a 68...

[jwc66k]

For once and for all ??  What is the acceptable date range between parts including drive train to the build date of the car itself . What is considered matching Numbers ?

For a Dearborn car, one day to a week before the actual build date as shown on a Marti Report. There are indications of up to three weeks in date codes to build dates. The "brains" will argue this point. Dearborn was close to most suppliers and did produce a lot of cars a day so parts had a quick turn. A special item, say a 428 Cobra Jet engine, may have sat around for an extra week or two, or not.
Jim

[67gta289]

All FE's including the 428 were assembled and tested at the DEP, and were transferred to the DAP without leaving the Ford Rouge grounds.  It makes sense that the Dearborn dates could be "tighter" for FE's.  Switching to the small blocks from Windsor or Cleveland, once the loading is done, what is the difference between transport to Rouge vs. NJ or SJ?  The offloading, handling and normal inventory assumed to be equal, I would think days, perhaps a week, depending on rail logistics.  We move a lot of product on rail and Chicago can be a mess.  A rail strike of course would blow that up, as did the Ford strike as Tim mentioned. 

Engines were prepped on a line at the assembly plants, and we are considering a process a couple decades before "just in time" was implemented to the extreme, so there had to be some inventory on hand.  Otherwise the plant management would not last long if they could not move product.  There is a balance between having engines laying around and shipping in batches.

As for specialty engines, it could be that something would sit around and have a bigger time gap.  Could it also be that they did not buck the car until the engine arrived, and the time gap was smaller?  Seems to me it could go either way.

All that to say that 67gtasanjose is correct in that the definitive answer comes from looking at other cars from the same assembly plant with the same engine.  Can't go wrong with that approach.

[Mike_B_SVT]

Don't forget that because your engine may have been assembled elsewhere it should have an engine assembly date stamp on it somewhere.
So the parts on that engine should be dated earlier than your engine assembly date, which should be dated prior to the car assembly date (of course).

As an example, my engine assembly date is 9/19 (of '69).  All the casting dates for block, heads, intake are dated prior to that (earliest is Passenger Head, dated 9G24 - July 24th, 1969).  My distributor is a "correct" part (the right part number / component), but is dated 9/21 (of '69), so it would not be considered "Numbers Matching" for my engine, IMO.

I imagine the transmission components would follow a similar rule ~ housing date vs tail date, should be close to each other.  Possibly bellhousing date as well?

[J_Speegle]

For once and for all ??  What is the acceptable date range between parts including drive train to the build date of the car itself . What is considered matching Numbers ?

Depends on how exact you want to be. In general (at shows and in judging) currently it will depend on the judge and his experiences and opinion

If you want something to stand behind (a reason you choose what you have) - look to other cars/ examples built at the same time and plant to best IMHO replicate any supply or other issues going on at that time.

[svo2scj]

I think WE ALL realize that if a car doesn't have the original Eng, Trans and Rear it can't be MATCHING NUMBERS but that also means a car can't have a matching drivetrain but been rebodied and be untainted either !

If you are talking about the ENGINE all items that are dated (Oil pan, front cover, manifolds etc etc) and even the sensors need to be prior to the ASSEMBLY STAMP on the motor.   Not many go to this effort , let alone have known to check the block stamp!  Batch items like carbs (if Holley) give you some room.

Car are really funny to look at !    It is easier to spot one that has been tampered with, had a fender replaced or put together wrong than most "builders" must realize!    WE used to use a term at the dealer "someone has been here" - when working on NEW CARS in for warranty repair.  (these were Jaguar's that owners weren't messing with per say)

I don't know if there can be a ONCE AND FOR ALL !    Certainly later cars from different plants change the "formula".    What is easier to explain a car that has a latter service block and earlier outside parts and has been maintained through out a warranty period or a car restored 30 years later in half way attempt to make "date correct"?

A very wise man once asked me AS I WAS ABOUT TO SPEND ALOT OF MONEY ON A PART....." to what mileage are you restoring your car?"  and that changed a lot about my attitude towards paint on that part!

Mark