Moz Ray

Great explanation of NOS taken from a Mustang forum. Although it is geared towards Ford Mustangs, much of the info is applicable to many applications . . . vehicles, parts, etc.

“I believe you're confusing yourself with the part #'s. The part # is a CONSTANT, and it has no relationship to the year the part in your hand was physically manufactured. The part # is created by Ford for the model year it first applies to, and then it survives forever until it is discontinued and/or superceded.

For example: A 65-66 Mustang RH front fender is C5ZZ-16005-A. Ford was still stamping these fenders into the 80's and 90's, but it was always labeled and identified as C5ZZ-16005-A. So, the part number identifies the part. Usually, the LABEL on the box or the part itself will have a cryptic date code that can give you an idea of exactly when that specific piece was produced.

Charles is correct, and I'll elaborate. When Ford original built the cars, they would place purchase orders with their suppliers for parts for "production", and concurrently, they would place purchase orders for the same parts for "service", which would be distributed by Ford Parts & Service to the dealers for over-the-counter sales, and dealer service department use. Initially, these parts were pretty much one and the same, as the suppliers were making the production parts and the service parts almost concurrently, with absolute priority toward production P.O.'s, and distant 2nd priority toward service P.O.'s. That just means that each supplier might have had their own individual trials and tribulations keeping up with production, which would push-back their abilities to supply to service.

Now, I'll start complicating things, to illustrate why the term NOS can be so damn confusing.

Since Mustang production was so enormous, Ford commonly had multiple sets of tools for a particular part, being produced by an array of suppliers. Once production CEASED for a particular model year, and a particular part was not going to be carried forward to the following year's production car, the part then was only needed for "service" exclusively. That meant the demand for the part went down significantly, which would cause Ford to re-negotiate and arrive with (usually) a single supplier to handle producing that part for the service demands into relative perpetuity.

Here, it gets yet fuzzier. Ford Parts & Service was much less stringent with it's quality-control than the factories producing cars. The level of scrutiny for tolerance and fit/finish by the factory was more (generally speaking) than the eyeball Ford Parts & Service was putting toward things. So while not ALL of the suppliers producing service parts would start half-assing it on their quality levels and fixture testing and maintaining, I can tell you from examining parts over time that some did, and Ford Parts & Service rarely did much about it unless a part flat-out wouldn't work, or bolt to a car.

FURTHERMORE, alot of the suppliers building assemblies were relying on 2nd-tier suppliers to make sub-assemblies, or components, that went into the final assembly. Sometimes a supplier would FIRE one of the 2nd-tier guys, or the 2nd-tier guy would not want to renew a contract, and the tooling had to go somewhere else, or they would source a generic part that would work somewhere else. NOW, you can see, that OVER TIME, the parts could in some cases start to MORPH. Still the same Ford part #, but the tooling beginning to wear, fall slightly short of the original aesthetic and functional tolerances, and small details possibly differing..

FURTHERMORE, when a supplier would complete a contract term for supplying a service part, Ford would commonly put that part out for "re-bid" to that supplier and many others. If the original supplier lost the bid, the tooling would get shipped off to some other factory, and who-knows whether it would improve, or degrade, or flat-out change in details or finishes. At this point, process sheets are getting lost, fixtures are getting tweaked, etc..

FURTHERMORE, there's a SEPARATE effort within Ford to cut costs and streamline parts, using one GENERIC piece for many different applications and part #'s, "because it'll work and save money". I've seen it go both ways... Ford would either discontinue ten part #'s and replace them with one new part #, or..., they would (this is always lovely, and I'm being sarcastic) just start plopping the generic and aesthetically incorrect part into the same old box under the same original part #. Those are great, you think you're buying NOS, and you get some modern "thing" that was designed and manufactured in 1985. Washer pumps anyone?

FURTHERMORE, tools would eventually wear out, and if demand was still strong enough through the service supply-chain, Ford would decide to restore the original tooling, or create all-new tooling. This is another avenue where, somewhere in time, the 70's, the 80's, specific details or characteristics of a part could change, still sold under the same old part #, but not really the same as what you would have gotten in 1968.

And as years pass, tooling moves, tooling gets fixed, componentry becomes obsolete and has to be resourced, but the part #'s stay the same and Ford provides a part that will work, until circumstances arrive where the decision is made to obsolete it. THEN, if the tool is salvageable, it possibly winds up somewhere like Carpenters or Just Dashes or Gerstenslager, and is reincarnated into a licensed "Original Ford Tooling" part, which is only as good as the condition of the tooling, and the folks building the part. In most all cases, they've done a very nice job.

So you see, there is NO WAY to easily explain what "NOS" is. It's not a rigid line drawn in the sand, it's not a yes/no answer. It depends on the part, and there's millions of 'em. The only way you can authoritatively navigate the sea of "NOS" parts, is to know what the parts were like on the production vehicles down to infinite detail. And you've got to have a decent sense of perspective, knowing when "close enough" is close enough to call it NOS in good faith. Because the term NOS involves such a complex array of VARIABLES, I believe it to be (from a practical standpoint) futile to take an absolute purist/extremist stand as it pertains to how people use the term NOS.

At this point, in the 21st century, when most of this stuff has been obsolete for over a decade, and only a handful of human beings really know the blow-by-blow lineage of any particular part, NOS works well as a term describing an new original service part or new production part (they're out there, but rare) that is more or less true to what originally came on the cars. Minor details differences will exist between production runs, and producers, but since the production parts were commonly produced by multiple suppliers, I believe that minor detail differences are o.k. to a point, and I suppose that point is where the judge scoring your car is SHARP enough to recognize them!! (Bob Perkins is a scorcher if he's doing your '69 or '70 LOL!!).

Where NOS is not NOS is when the part in the box is just a generic "will work" part that Ford exchanged/swapped for the original-style due to streamlining, cost-cutting, original tool wearing out or breaking, or whatever other screwy reason they may have had. It's also not NOS if it's a licensed re-issue, although sometimes those re-issues are cosmetically and functionally better, as the folks doing it are paying better attention and care more (Carpenter).”

Plasticman

Great info, and certainly most of it applies to GM as well.

Thanks,
Plasticman

JohnZ

And in the wonderful world of eBay Marketing 101, most sellers use "NOS" to describe any part that's in a box with a number on it or any part that isn't too rusty, so they can suck in the folks who don't know the differences between an original assembly-line part and later service replacements. 99% of the stuff on eBay that's described as "NOS" (new old stock) is actually "NORS" (new old replacement stock), but NOS is the "magic word" that draws the less-knowledgeable bidders to open their wallets.

AZDoug

And in many cases, NOS, simply stands for Nasty Old ****, as is seems that a lot of 1960's stuff that didn't quite meet QC for assembly line production or was slightly flawed ended up in parts boxes for sale at the parts counter a few down the road.

Doug

knight37128

Does anybody have the Cliff Notes?

I'm not reading all that Found On Road Dead stuff.

Chuck Gongloff

Best explanation I've ever read.

Should be required reading for restorers and EBAY sellers.

Chuck

Paul L

Well, I've learned something. I thought NOS was service replacement parts of the time in question available over parts counters. How would GM dealers and/or the general public get access to parts intended for, and presumably used on, the production line?

JohnZ

There was no general access to production-line parts, except when they were catalogued and stocked by GM as service parts as a coincidence. Service parts were stocked to functionally "service" a given application or group of applications, and whether they looked exactly like the original production part wasn't important - the criteria was whether the part would be a "functional" replacement, and appearance wasn't a consideration.

Paul L

So "true" NOS is what was used on the factory floor. That definition certainly crimps the real NOS market to a very small size! And brings a whole new meaning (for me at least) as to why NOS parts, and NCRS restorations, are so terribly expensive. The $10,000 1967 EBay wheels for example. Not to mention $75.00 air cleaner wing-nuts and oil drain plugs. Interesting thread; thanks for starting it. Again, I have learned something.