Since august of 2021 I have tried to dig into this “Myth”, and collected as much information as possible, and systematically inserted it into excel. Mostly pictures of chassis plates from vehicles found on the WWW are used as information. But also, information from the spare parts catalog`s – homologation documents – owner’s manuals – FIA documents – Fiat Service Bulletin – books & here on FDF.
And in my opinion, the “key” to solving the myth, is actually the spare parts catalog`s! But it has been a little difficult to get hands on properly updated spare parts catalogs. Why, well when the vehicles were launched the base parts catalog was released to the dealers, and during the changes in the production, update sheets were sent to the dealers, for replacements & inserts! And here the problem starts, since the Dino was a low volume model, updating the parts catalog at the dealer site, seems not to have been a priority! Most of the catalogs available for sale/ in collections are mostly the base catalogs with some few updates, and the 2.0 catalogs seem better updated, compared to the 2.4! But finally in October 2022 I managed to find a completely updated Dino 2000 parts catalog, updated up to February 1970 with the last update: Modifiche D3460.
So, my theory and what I will try to proof, is that all Fiat vehicles where produced in increasing order by the Ricambi number, and not by chassis number!
Why?
1. The “Numero per ricambi”:
Every Fiat (not only the Dino) has a unique Ricambi number stamped on the chassis plate. Italian`s also call this the “Vett number” (Numero di Vettura), which means vehicle number! The “Vett number” reference in the spare part catalog is very often misinterpreted as the chassis number, but a chassis number is called “Autotelaio” in the Italian language! And all the changes in the spare part catalogue refers solely to the Ricambi No., with some exemptions where it refers to the production month or engine number, but it also refers to the Pininfarina body number in the body parts catalogue on the Spider!
So to my best understanding, the vehicle modification in the production line was like this : When a modification was implemented in the production line at the Fiat factory, it was noted in the parts catalogue at which Ricambi No., Pininfarina number, month or engine number this modification took place by a “C & D” version (C = Last “Vett” before modification implemented – D = First “Vett” modification was implemented). This logic follows on all Fiat models spare part catalogues on paper & microfiche but disappeared in the end of the 90`s with the digital parts catalogue ePER.
And by this the Ricambi No. must be the production number, otherwise the ordering of spare parts at the dealers would be a total mess! Another interesting thing with the Ricambi No., is that the Ricambi No. on the BC/ BS is a continuation of the Ricambi No. from the AC/AS! So the Ricambi No. will also tell us the exact production figure`s, if I/we manage to find the last one
I have two theories/ explanations why the chassis numbers are not in increasing order in the production line:
a. Some customers ordered different options like leather interior, metallic paint, air condition etc, this chassis was taken out or delayed before it entered the “production line”, when the options/ changes where implemented. Then the chassis was put into the production line again.
b. The chassis/ bodies arrived Fiat a little random with the delivery truck`s from Bertone & Pininfarina (B&P). Because they entered bout the trucks at B&P and the production line at Fiat randomly, independent of the chassis number. This is maybe the most plausible explanation, or maybe there is a combo of both? If you also look at pictures available from the production line of the Fiat Dino, you can see that the Coupes and Spiders are randomly mixed in the production line. So, my theory is that the chassis plate got stamped with increasing Ricambi No. directly on the production line (Independent of the chassis number), and the production changes was implemented simultaneously on bout Coupe and Spider. The Ricambi No. when the change was implemented was then noted in the spare parts catalog`s. This also makes the production line more effective, since they don`t need to control that the chassis numbers are in increasing order at the production line!
2. B.I.T. – Bolletino Informazioni Technice:
After been writing this and reading the parts catalog multiple times during the last year, I became aware of a “notice” on the side in the “Modifiche” pages in the parts catalogs in 2022, where the “C & D” changes are noted. There is a notice like “B.I.T. 236V” on Modifiche 3102, so I was wondering what is this “B.I.T. 236V”? Well, in the “Use of the catalog” it is explained: B.I.T.: Bollettino Informazioni Tecniche. In English it is written: Technical bulletin in which the modification is described! So, this made me very curious, and after Googling a lot, I found one B.I.T. for sale on EBAY (Thank you Toni), and B.I.T. is actually a technical parts bulletin explaining the changes Fiat did in the production line, this is how Fiat explain B.I.T. on the front page of the bulletin I bought:
B.I.T.238V (which of course has no info regarding the Fiat Dino):
"The Technical Information Bulletin serves to bring the Spare Parts Catalogs up to date with modifications introduced in vehicles during production.
For each modification published, identified by a number, the Spare Parts Catalogs concerned are indicated.
Illustrations will always show the Ante-modification and Post-modification solution to facilitate the interpretation of the modification and the comparison between Ante-modification parts "C" and post-modification "D".
So now I got even more curious about this B.I.T., and would it be possible to find all the B.I.T. documents mentioned in the parts catalog? Well in the autumn of 2022 I contacted the archives at the Fiat Historical Center, and asked if they had this B.I.T. documents available in their archives, and to my surprise, they had all of them except one! But the catch was that they could not help me with copies, I had to personally visit the archives, to see the documents. So, then the summer holiday of 2023 was set, and my family & I drove to Italy (Liguria)
When reeding the B.I.T. document`s, I finally found the “line of proof” in B.I.T. 239 from 18. March 1968, it is written:
Modification 3116:
Ante-modification: Flexible joint companion flange secured to the primary shaft by a nut & lock washer (See C)
Post-modification: …….. by staked nut (See D)
Attuazione: Dal veicolo con N.° per ricambi: 000728
Effective: From vehicle with No. for spares: 000728
So, in my opinion this is actually the proof that all Fiat`s are produced in increasing order by the Ricambi number, and not by the chassis number!
And this is also the proof that Fiat had FULL control of the parts in the production of every vehicle.
The “Typical Italian chaos” rumor you can read & hear about everywhere: “Fiat took whatever they had of part`s in the shelves & throw it on the cars on production line”, is by this disproved!
You just have to read & understand the parts catalog

Regarding the 2400, there is no references to the B.I.T. in the parts catalog`s, so seems like they stopped with the B.I.T. documents at some stage around 1970!
I will show you the info I have collected, and will start with the AC, and then continue with the AS, BC & BS on every Saturday in the 4 next weeks (Maybe we get some action here on FDF again
So check that your FDF login credentials are working, so you can access “The library” and download the 1. documents next Saturday (2.december)
Erik