If a car was built in 1972 when would the block and heads be made? Would the date on the heads be the same as the heads? When numbers matching is said does that mean actual engine and stuff the car was made with or does that mean the proper era the car was made. Like car was built june 72 and the engine trannt and others built before that. Can a car be a numbers car but not with original parts but with proper dates.

That's alot of questions.

Virtually all blocks/head have dates before the build-date of the entire car- engines/heads are cast and assembled almost always in a completely different plant than the car itself is assembled. And, way back when- in the days before "just in time" manufacturing- nobody was in a huge hurry to shove things out the door- so if a block sat on a rack for a year before being put in a car, who cared?

Now- technically, a "numbers match" vehicle has the exact same engine, heads, etc. etc. that it left the factory with- i.e. the original parts. However, as time goes on that has gotten a bit more flexible and now basically includes engines/heads/etc. with the right date codes and application code (i.e., say a 1972 Camaro RS w/auto tranny) that were the same as used in the car when it left the factory (the point being that no one can really prove beyond the date/casting/application codes that it isn't the "original" piece) so people are forced to accept that they are because all indicators can't contradict it.)

So- yes, if you have all the right date, casting and application codes on your pieces, it is by all accounts a "numbers matched" car. Just don't try to sell it as "all original" if the previous owner is ready to swear out an affadavit that he still has the factory-installed engine sitting in his backyard.

An engine may have several different date codes for the block/head1/head2/crank/cam.

MELTING: As we pour the iron & make castings, each run will have a specific date code and shift code, as well as hour stamp.

SHAKE OUT: These castings are taken to a shake out area, where the castings are shaken out of their sand molds. Then they are palletized for the rough finish area. Castings can fall off the conveyor & be placed back on the conveyor days or weeks in between.

WAREHOUSE: castings are placed in rows for rough processing. Each row is supposed to be in FIFO (first in first out) order, but that's not the case all the time. Factors such as forklift driver error in selection of the pallets, along with containment for iron testing will change the FIFO order... as well as fallen parts that will be reinserted into the process at a later date. Sometimes a new run needs to be shipped ASAP for testing & approval.

ROUGH FINISH: Castings are cleaned & excess metal is removed. Some castings are sent to salvage for extra work and some are sent to scrap for disposition. Some or all of these may be placed back into the system at a later date. Some will be remelted. Also, we have a float system where we take parts off mid-line to supplement the line when there is downtime somewhere else. Floated castings can sit for days and contain several cast dates.

SHIPMENT TO PAINT SHOP: When the castings are approved for shipment, there is a majority of a certain cast date, but it will be peppered with several other cast dates from salvage, non-scrap, float and differences in forklift driver choice in loading the line FIFO.

PAINT SHOP: Again, forklift driver choice in choosing what pallets go first & last, as well as factors such as machine downtime, 3 paint lines, etc..

ENGINE PLANT: Most engine plants will have forklift drivers choose what is loaded first. Then the castings are loaded in no particular order into the broach machine. From this point, the machine line will have SEVERAL float off stations that will mix up the cast dates even more. Then the finished machined casting is forklifted to the engine assembly area warehouse. Then a forklift driver will choose which pallets go to the final assembly area for final disposition. At this point, complete engines can be floated off for repair disposition, which may include a different head.

IN SUMMARY: It is not impossible to have your block & heads all match dates nowadays, but it is unlikely. From the point of a casting pour until the engine is assembled, a single casting may make the trip in 3 days up to 2 months after the casting date. that's a lot of days in between for you to roll the dice to get all castings match dates.

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