I've called Marcel Massini to have a "final" answer about all those "noises" occuring from every potential dealer/seller regarding the Daytona "A" suffix since several years.
He sent me the prepared comment which will answer most of the questions arising regarding the "A" suffix. I also have to admit that the information given to me is much more detailed I ever expected and by way much more than the answers provided in Gerald Roush's book "Daytona". I would like to thank Marcel's for his kind permission to publish his comment here!:
Ferrari 365 GTB/4 and 365 GTB/4A
In the beginning there were only Euro model 365 GTB/4.
So for the first series of Euro cars, as per the Italian homologation papers for the 365 GTB/4 the early Euro model 365 GTB/4 was homologated by the Ministero dei Transporti del Aviazone Civile - Direzione Generale Motorizzazione M.C.T.C on Nov. 3, 1969, with certificate 7230 OM. According to this document the stamping is 365 GTB/4 *00000* with the addition of DGM 7230 OM (DGM = Direzione Generale Motorizzazione).
And then we go on to Euro model pop-up light cars starting on June 19, 1971 there was an addition to this homologation (for European cars) concerning the pop-up lights and the single reverse light. These Daytona's are named 365 GTB/4-A and the homologation starts with chassis #14175 (Rosso Rubino 106-R-12, leather Rosso 101. Assembly sequence #451, factory completion date 26th February 1971). Accordingly the stamping is 365 GTB/4-A *00000* DGM 7230 OM.
The last page of this document is the "Dichiarazione di Conformita" with which Ferrari confirms that the vehicle is homologated with the Certificate 7230 OM and they list the type and series (tipo e serie) as 365/GTB4 (x).
So... a Euro car with pop-up headlights and a centered back up light, that's it!
So all Euro cars up to s/n 14175 were covered headlights when new.
All Euro cars starting with s/n 14175 have pop-up lights and two reverse lights under the rear bumpers. Only the US version had a single centred back-up light.
No different cams, no different carbs, no different rear gears, no more power, NOTHING!
And then we have the USA cars starting with s/n 13361 which was the prototype USA version Daytona, and therefore had pop-up lights.
S/n 13893 was the first production USA version Daytona, so pop-up headlights as all USA Daytona's had pop-up headlights.
The "A" cars and indeed all Euro cars have about 15hp - 25 hp more than a US Daytona, because the US Daytona has a smaller inside diameter (and very restrictive) exhaust header.
The US version had heads 1 mm. higher than the european version, so a slightly different compression ratio.
Maybe this has been answered, but I'm confused. in the text of Marcel's comments, it says,
"there was an addition to this homologation (for European cars) concerning the pop-up lights and the single reverse light. These Daytona's are named 365 GTB/4-A and the homologation starts with chassis #14175"
This is followed by,
"So...a Euro car with pop-up headlights and a centered back up light, that's it!"
But then the confusion comes when further down it says,
"All Euro cars starting with s/n 14175 have pop-up lights and two reverse lights under the rear bumpers. Only the US version had a single centred back-up light."
i will try to post what i have learned. anyone is free to make suggestions.
it will be easier if we ignore the usa daytona version for now. just considering the euro daytonas.
consider two categories:
1-early euro daytona
- plexi nose
- aluminum doors
- 2 reverse backup lights
2- late euro daytona
- pop up headlights
- steel doors with internal reinforcement
- single centered backup light
now to consider the usa daytona version. these are the brief differences between usa and euro daytonas
-pop up headlights
- single centered backup light
- smog pump
- more restrictive exhaust
- different carb jetting
- lower compression ratio due to heads being thicker, possibly for the air injector pump nozzles
there are also slight differences between early and late daytonas but not really worth mentioning.
i suspect that many anecdotes of the euro daytona being faster may be due to the fact that:
1- less restrictive exhaust
2- higher compression ratio
3- many euro cars lack the weight of the smog equipment, air conditioning and steel doors.
this is a very brief description as there is a ton of minutia not listed.
hope this helped.