Production vs Service Parts

[Dan Case]

This week a set of side discussions related to "original" equipment versus service parts for Cobras (CSX2xxx leaf spring chassis.) has taken place between various parties. I thought it might be appropriate to put a copy of a post I keep on the SAAC CSX2000 Series forum here for this audience.

Dan

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Production part or service part?

For historical accuracy, beware of using the 1965 and 1966 (published in 1965 and 1966) Shelby American service parts books for Cobra and 427 Cobra repairs or restorations. The yearly race season forms and within seasons revised forms Shelby American submitted to the Fédération Internationale de l'Automobile (FIA) race sanctioning organization for Cobras can also get one historically lost as some parts were not described enough to know exactly what was being listed or the picture(s) included might have been what was planned and not necessarily what was used; the prototype intake for Weber down draft carburetors comes to mind, it was a wooden mock up painted silver. There was a 427 Cobra chassis Bill Of Materials published that included a cross reference of AC Cars and Shelby American identifications. It is a very interesting document but it too must be used carefully as to me it appears to be what was planned before the first chassis was built and not what AC Cars actually built for any of the coil spring chassis contracts. Also do not rely on the aftermarket accessory catalogs that Shelby American published 1966-68. These published works were not 'here is what AC Cars/Hugus/Shelby/Ford "as built" the cars with' set of references. None of the Shelby service and accessories parts books address evolution of parts well as ‘new’ versions or designs got replaced ‘old’ parts; stabilizer bar grommets and mounts come to mind as 1963-64 pieces and 1965 pieces are significantly different parts doing the same jobs. None of these publications directly addressed the many changes in new chassis within or between contracts for chassis. It was critical from the start for dealers and owners to know the chassis number of the car they were making parts inquiries for. Without knowing the chassis number the chances of getting the correct service part(s) were less than perfect. There were quite a few differences in an early CSX20xx car and a late CSX20xx car and a late CSX25xx car was very different parts wise. (Note: COB and COX prefix chassis were a little different to very different from the CSX chassis that were built concurrently as AC Cars home market specifications were different from American market specifications in many ways.)

The Shelby parts and accessory books were in part lists of commonly serviced or replaced parts and in part lists of post delivery accessories. Many of the parts listed were just things that will do the job. Most of the parts AC Cars used in building the chassis were not included. Many of the significant parts for early Cobras were not listed at all. The racing and accessory parts listed were not always the same things installed on new cars street or race. Regarding racing accessory catalogs, Shelby American often used one thing on their team cars and something else on customer cars or through the parts department.

These books also did not include a lot of the small parts SA sourced or made on their own locally without going through Ford or AC Cars.

Also, beware that for Cobras that the AC Cars chassis manuals also include service parts that were different that what was used in production. I have even found an omission, i.e. a part used in new Cobras not shown in the drawing in the manual or associated parts list.

Also bear in mind that chassis were built and finished into running cars street and race over several years by different groups of people in different shops in different countries; there were prototypes or engineering specials; street chassis were occasionally finished into racing cars; chassis were specifically ordered and built as race chassis; ‘team’ race cars often changed a tiny amount to a lot race to race. Bear in mind that a part or material available on a given day in production might have been replaced by a different or improved version weeks or months later. The published parts information barely makes an attempt to delineate any of these variations.

In general to get a good idea of how any new Cobra might have been outfitted one has to know the chassis number, when was the chassis finished as a roller, when was the unit finished into a running car, was it a street car or race car day one, was it built to custom specifications day one or modified into a working test vehicle by AC Cars or Ed Hugus’ shop or Ford Motor Company or Shelby American, and which shop did the final assembly for any ‘stock’ street car.