As I mentioned, Alfa revised their numbers over time. There are 3 versions of the Owner's Manual and at least 2 versions of the Technical Specifications. The newer numbers for ignition advance are:
3° +/-1° @ 750 RPM
43° +0/-3° @ 5,000 RPM (changed from 47° +0/-3°, which was changed from 47° +/-3°)
I don't recall seeing changes to the Low Speed advance information but would expect it to be 4° less as well (changing the nominal value from 27° to 23° before adjustment for non-leaded gas) but I did not include such a change in my spreadsheet until someone can confirm it. Furthermore, I don't know if Alfa ever changed the crankshaft pulley markings to reflect the changes in advance settings.
Please note that in the tech. bulletin page copied below (dated 02-Dec-64), Alfa advised to reduce the max. advance from 47° to 43° for switching from Lodge 2 HLN (adjustable gap) to Lodge 2 HL (fixed gap) spark plugs. I would presume this change applies to all modern spark plugs (e.g. NGK BP7ES).
[SIZE="1"]'63 2600 Touring Spider (AR 191437, the car that started the 2000/2600 International Register, reassembly in progress)
ex-'65 2600 SZ (AR 856043, the car in my avatar, sold as resto project to Austria)
Maintainer of a private 2600 SZ register (not the one in the Netherlands).[/SIZE]
Last edited by tubut; 08-03-2009 at 02:05 PM.