Differences on first day cars vs. regular 1964.5 Mustangs.


Here are some
of the things
to look for in
a 1964 mustang
made on the
first day of

First day car vs.
a regular car.

Bob Fria, who currently owns production 5F07U100002, has put together the research below on rare mustangs made in the first 30 days of production.

Note from Bob:

Finally after gathering all the information that I could to attempt this research, I have been able to make sense out of the preproduction car radiator support codes we have all wondered and speculated about. Although this has taken much longer to accomplish than I anticipated, the results were worth the effort.  Many changes occurred since the original document I sent you and subsequently revoked due to newly uncovered documented information. Much of these results are based on newly found FoMoCo file documents, indisputable evidence.  I hope you are able to digest the results of my research and in the hopes that I have shed some light on the subject and if you now will have a better understanding of the sequence in which these cars were built, I will feel the project was a success. Those of you that assisted me in providing the data used are thanked sincerely.  These good folks are: 

VIN 100006    Allan Shepley             Byron, Georgia
VIN100047     Leonard Finn               North Carolina
VIN 100129    Klaus Schaefer           Newel, Germany
VIN 100170    Frank Middleweek    London, England
VIN 100173    Frank Middleweek    London, England
VIN 100280  Chuck Carter               Midlothian, Virginia
VIN 116036    Steve Grant                 Los Angeles, California

Again, thank you for all your cooperation. 


July 23, 2006





By Bob Fria

LaCrescenta, California

PURPOSE: To decode original radiator support inked dauber markings to validate an understanding of chassis build sequencing prior to the formal start of production of the Mustang car on March 9, 1964.

On the front right side of the radiator support of every Mustang assembled at the Dearborn Assembly Plant, at least through April, 1964*, there appears four, sometimes five lines of distinct lettered production code. This code was always located and printed in lines between the radiator opening cutout and the vertical cooling louvers just in front of the battery area. The coding was hand written with an ink dauber and then, during the paint process, was painted over when the radiator support was painted black and thus disappeared from view.

As the cars aged over the years, the ink dauber markings were protected by the paint. Because of the chemical etching process between the radiator support metal and the ink dauber ink, the codes were in most cases, indelibly and permanently etched into the metal. Careful chemical or bead blast paint stripping of the radiator support for restoration reveals these etched code markings. From these codes this research has revealed some interesting facts and allowed certain conclusions relating to the sequence in which these cars were assembled. My sole purpose in this individual project is to further study the early build process so automotive historians may better understand the evolutionary process and the assembly sequence of these early Mustangs.

As owner of hardtop 5F07U100002, I already had access to information from this car. I was able to contact several other special use, export and pre-retail-production car owners and early Mustang registrars and obtain the data used in this project. Information provided to me is presented in the attached chart. This information was taken from photos and actual sightings recorded by the provider and made available to me for this project. Every attempt was made to verify the correct information transmitted to reduce the possibility of any error being introduced. I believe all factual information presented here to be accurate and correct as of the date of this report.

To be sure, other (special use, export and pre-retail-production)** vehicles will surface as time goes by and more revelations may be forthcoming, but for now this is what we have to work with.

* Unable in this report to authenticate further beyond this date

** defined as vehicles with DSO numbers in the range 81 - 99

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It is doubtful convertible 5F08F100001 located in the Henry Ford will ever have its coding revealed, since the Museum has no plans to further restore the car. (I did personally inspect this car myself and no evidence could be seen of these markings as the area remained covered with its original paint).


Focus of this investigation is primarily on Line 1 code which may reveal assembly sequence of these pre-retail-production vehicles while further providing insight into which cars were produced first through last in the series. As can be seen from the chart, each vehicle used for this research starting with the earliest VIN is listed with its four or five lines of code indicated as found on the radiator support. The data base is very small; however certain correlations can be immediately seen. The first or top line code always starts with a letter and has a numeral assigned to it (ex. A15). This code identifies a 2-rail chassis assembly skid upon which the partially assembled chassis was placed. As the skid moved down the line, body part assembly was referenced to the skid since no VIN was in place. Once the VIN was stamped on the body and the chassis painted, a paper broadcast sheet providing further detailed instructions for assembly was taped on to the same area of the radiator support. The second line code lists the body type, i.e. hardtop (65A) or convertible (76A). The third line code shows both letters and numerals. The letter, from this limited data base, always shows the exterior color code for the car. The single numeral used with the letter appears to be code for the interior painted color appointments. On Line 4, only one vehicle shows data on that line. The purpose is unknown although it may have to do with an accessory to be installed, such as a Power Top (PT). Line five seems always reserved for an accessory installation, and in most cases here, each car has the letters “BL” coded. It is strongly believed from other research this particular code called for the installation for Back Up Lights, an optional accessory. One car had “RM”, which is believed to be Rocker Moldings.


The eight cars listed here all have data plate production codes of 05C (March 5 th). From previous research on my 100002 hardtop, it is believed approximately 180 cars were assembled and are commonly known as special use, export or pre-retail-production cars. My 100002 car, as best can be determined from date codes on all date coded parts and unique welding marks, was preassembled in January at Allen Park and was finished most probably after February 7 th and before February 11 th , 1964. It has an 05C data plate date code. The other known cars referenced here also have date codes of 05C, up through 100173. Obviously, all these cars were not produced on March 5 th. This is known because we have the tentative build date for the twelve New York World’s Fair cars established as February 11 th starting with VIN 100006. The DAP was shut down on Friday, February 7 th for the change over to integrated Fairlane/Mustang preproduction and restarted sometime prior to or on February 11 th.

By February 28 th, 150 Mustangs had been produced. Generally speaking, vehicles with VINs of 100150 or less were built by February 28 th. The remaining 30 – 50 05C VINs were most probably built between March 1 st and March 5 th by skeleton assembly line workers. By March 9 th, the first day of scheduled retail Mustang production, most DAP workers had returned to work the line after the changeover.

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After this date, the production line at Dearborn was devoted exclusively to Mustangs and no more Fairlanes were built on the Dearborn line. That production was moved out of state.

Following the line of thought that all special use, export or pre-retail-production vehicles were built prior to a pre-assigned single date which preceded the first date of actual assembly line retail unit production at Dearborn, and that all were given that same data plate production date, I investigated other Ford special use, export and pre-retail-sale known production vehicle VINs through various public registries. The information developed supports the theory that Ford does in fact assign what appears to be a preplanned single production date code to all special use, export and pre-retail-production vehicles assembled in other car lines. For example, Thunderbird date coding was examined. In the production year 1962, VIN numbers 054,118 and 158 all have date codes of 28H(28 August). Production year 1964 VIN numbers 070,073 and 109 all have date codes of 08H (8 August). Note the numerical sequence spread of these VINs. All of these cars were not assembled on formal start date of DAP assembly line retail production, since we already know Ford builds possibly up to two hundred pre-retail-production vehicles for special use, display, promotion, testing, etc. Therefore it can be logically presumed that all of Ford’s special use, export and pre-retail-production vehicles assembled are given same day predetermined production dates close to but always preceding the first date of Dearborn Assembly Plant retail car production apparently as an administrative convenience. In the case of the early Mustangs discussed here, March 5 th (05C) was assigned to all of the special use, export and pre-retail-production vehicles. Following this presumption, then how do we know when or in what sequence these special use, export and pre-retail-production cars were built? This is where that first line of radiator support code becomes relevant.

As we examine vehicles in the chart, 002 displays Line 1 code A15, 129 code B40, 170 code C19 and 173 code C22. This first line coding on radiator supports we now know was used by the Detroit Assembly Plant workers and was applied there. The coding was identical to the coding being used on the Fairlane radiator supports which was applied in the same way. This code identified a numbered chassis assembly skid (Tool #49-ZF-3089) on which a particular chassis was built. A unique correlation can be seen between VINs 170 and 173. 170 has Line 1 code C19 and 173 has code C22. Numerically, these VINs are three numbers apart, the exact spacing between C19 and C22. These two vehicles were assembled in sequence three positions apart. One would presume the numbered skids were used sequentially, but that may not have been the case. Vehicles were assembled with skid numbers not necessarily designating assembly position. Example: VIN 002 with a first line code of A15 (see attached photo), would have been mounted on assembly skid A15 while on the line. These cars were assembled, all or most prior to March 5 th. However, it will probably never be known if these cars were built in exact numerical VIN number sequencing, uninfluenced by actual dealer order, or whether the VINs were intermixed for whatever reason, as were the production cars built on or after March 9 th. These we know were built out of exact VIN numerical order based on dealer order numbers. It is substantiated the 100002 chassis and several others were produced at Allen Park and then truck transported to DAP to be used upon the start up of factory pre-retail-production well before March 5 th. Were there skids numbered A1 thru A14 and were they ever used? We don’t know.

Research on several other very early cars supports the skid theory. VIN 100280 has a date code of 10C and Line 1 code B16 (or 26). The first day of Dearborn assembly line production according to Ford was 09C, March 9 th. This vehicle was built on the second day of production on skid B16 (or 26).

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Later on, another example, VIN 116033 was given a first line skid code D795, and 116036, a Pace Car hardtop, built on 20D (April 20th), was given a skid code E320, indicating the chassis was built on skid E320. How long this coding was continued in use is unknown. One question previously unanswered is if the VINs of these preproduction Mustangs were intermixed with the Fairlane cars. The answer is now clear by investigating Fairlane VIN numbers. All Fairlanes built as 1964 models had the year 4 at the beginning of the VIN. Since all Mustangs had 1965 model designations, they had 5 as the VIN first number. Due to the model year difference in VINs, the sequential numbers could never be intermixed due to the two separate model years. Therefore, no Fairlane VINs are intermixed with Mustang VINs, leaving the Mustang VINs as purely Mustang.


According to my research interview of April 25, 1999, with Mr. Bob Negstad, Mustang Project Chassis Engineer responsible for developing the new Mustang suspension, the few incomplete Allen Park chassis that were not damaged, destroyed or needed further by Allen Park were transported to the Dearborn Assembly Plant to be used as production chassis for Ford usage and retail sale. Once placed on the assembly line with other DAP produced cars, they lost their Allen Park identity and were assigned actual VIN numbers. He stated none of these few chassis had Dearborn assembly line VIN numbers while they were at Allen Park.

How then does the Line 1 code relate to the VIN numbers? It doesn’t. From the data obtained, it appears the VIN numbers were assigned in ascending numerical order as the cars moved down the line. The skid number did not necessarily correspond sequentially to the VIN number. Were there VINs assigned to the skid chassis numbered before A15? Or were there other prior numbered skids used at all. Or were there even any skids with prior numbers. None of those vehicles with earlier skid numbers are known to exist, except possibly for 5F08F100001 which is in the Henry Ford (museum), and its code remains unknown. Possible explanations for unknown VINs are that some of those chassis may have been damaged or did not meet specifications in assembly, were destroyed, or were used for test purposes and never assigned VIN numbers in assembly. This would explain the gap between skid number and VIN number sequence. VIN 001 may have had some skid number prior to A15. If so, then we can presume there was at least one skid numbered prior to A15, and others may also have existed. To date, no one knows for sure.


It is generally true that when Ford assigns a VIN number to a chassis, it is in response to a dealer order for a retail unit. It becomes apparent looking at VIN numbers versus DSO (District Sales Order) numbers, that these special use, export and pre-retail-production units had only Ford internal usage DSOs assigned on the Dearborn assembly line. Such cars were then designated to

be used for government, Home Office, Ford Transportation Services, export, etc. purposes. DSOs other than Ford internal number designations did not start appearing on data plates until 09C (March 9 th) when the Dearborn production line started. The first known domestic DSO order from a dealer appeared with 100212* on 09C for delivery in the Jacksonville, Florida, district (DSO area 24).

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Looking further at the Thunderbird DSO records, we see no external domestic Ford DSOs were assigned to the first known pre-retail-production units built for the years of cars examined in the 1960s. Further support that all of the 05C special use, export and pre-retail-production Mustangs were built for some special use requirement by Ford, and not in response to a specific dealer order.

* Ref: Mustang Production Guide, Vol. 1, pg. 59, by Smart & Haskell


For now, existing evidence researched here seems to prove any Mustang with a data plate date code of 05C (March 5 th) is in fact a special use, export or pre-retail-production vehicle with final assembly at the Detroit Assembly Plant. This may have amounted to as many as 180 to 200 vehicles.

How many of the few Allen Park assembled pre-retail-production chassis were actually sold later as retail units with actual DAP VIN numbers remains unknown. Some may certainly surface in the future. When they do, if their radiator support codes can be made visible on these DAP Mustangs, all with VIN’s less than 100200, it is my opinion they will give further evidence to prove the above theories and fact as to the actual sequence in which these early cars were built.



I have owned the first production Ford Mustang hardtop to be assigned a VIN number since 1997. I have owned other Mustangs since 1976. Ownership of 5F07U100002 inspired me to research as much of the history of that car as was possible, and it is still an on going process.

During that research, I was able to decipher much about the techniques and process used to develop the original Mustang 2 seater, the Mustang II and the early Allen Plant pilot cars. I have authored numerous articles published nationally relating to the origin of the Ford Mustang and the production of those very early chassis’ produced by Ford.




100002 100006 100047 100129 100140 100145 100170 100173

DSO 81 *84-0027 ** ***15 89 89 91 91



Line 1 A15 B3- B40 C19 C22

Line 2 65A 76A 76A 76A 76A 76A 76A 76A

Line 3 H2 M5 RM*** J6 J6

Line 4 none PT none none


All above vehicles have a data plate production date code of 05C (March 5 th, 1964).

*100006 codes previously obliterated – none readable. Worlds Fair ride car verified.

tentative build date February 11 th for 12 Worlds Fair ride cars.

**DSO not known on 100047 – (Styling Dept?) car listed by Ford as having a rumble seat

***DSO 15 Newark/ sale to World Wide Military Sales by Levitown Motors, Levitown, NY

100129 Line 3 data – previous owner reports not sure of “RM” – difficult to read.


100280 116033 116036

DSO 23 22

Line 1 B16 (or 26) D795 E320

Line 2 76A 76A 65A

Line 3 A85 A85 C42

Line 4 none none

Line 5 BL RM BL

100280 data plate production date 10C (March 10 th, day after official production start date 09C)

100173 (05C date) and first known 09C date (100212)* tends to confirm approximately 180 – 200 + preproduction cars were assembled if all preproduction cars received VIN numbers

116036 verified as an Indianapolis factory Pace Car (paint code C only used on Pace Cars)

* Ref. Mustang Production Guide, Vol. 1, pg. 59, by Smart & Haskell


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