Just to list the different setup possibilities (thanks to Kanga) :

Anti roll bar Front Part # Stiffness**
1. 4G43-5494-AB DB9 Std (V8V Sportspack 26.5mm ?)
2. 6G33-5494-AB DB9 Sportspack 07MY (88% V8V Std 25.6mm)
3. 8D33-5494-AB DBS (114% 28.0mm)

Anti roll bar Rear Part # Stiffness**
1. 8D33-5A771-AA DBS - V12V Std - V8V Sportspack (29.0mm ?)
2. 4G43-5A771-AA DB9 - 57% Standard 25.2mm
** Stiffness shown as a percentage relative to the V8V Sportspack anti-roll bars.

Vantage spring rates:
V8V 4.3 ------------- F 265 lbs / R 493 lbs
V8V 4.7 ------------- F 295 lbs / R 531 lbs
V8V NITRON NTR1 --- F 375 lbs / R 425 lbs
V8V4.3 Prodrive ----- F 442 lbs / R 708 lbs (electrically adjustable dampers)
V8V4.7 SportsPack -- F 531 lbs / R 590 lbs
V12V6.0 ------------ F 531 lbs / R 590 lbs

What is your setup ?
Other possibilities ?

 

Anti roll bar Front Part # Stiffness**
1. 4G43-5494-AB DB9 Std (V8V Sportspack 26.5mm ?)

Anti roll bar Rear Part # Stiffness**
1. 8D33-5A771-AA DBS - V12V Std - V8V Sportspack (29.0mm ?)

Nitron single adjustable shocks with 575lbs front and 625lbs rear springs

 

2 AM sportspack kits :

Uprated springs and Bilstein aluminium dampers
- 6G43-23-10456 Coupe
- 6G43-23-10457 Roadster

Lightweight, five-spoke alloy wheels
- 4G43-36-10704 Sports Pack Wheel Kit

 

Something strange for me, on astonmartintechinfo :
- 4G43-5494-AB DB9 Std,
- 6G33-5494-AB DB9 Sportspack & V8V Std

So I don't understand why :
the DB9 Std become the sportspack for the V8V,
while the DB9 Sportspack become Std in the V8V ?

 

Bruno-where did you find the OEM spring rates and in particular the sport pack at 531/590? Stuart had told me the sport pack setup was 411/457.

 

Kanga give me the values

 

Reviving this thread once more...

I have a 2007 4.3 Vantage Coupe non Sportspack and purchased the Sportspack anti-roll bars (6G33 front, 8D33 rear) for better roll control. I figured the front 6G33 bar would be thicker than my current stock bar, but it seems to be thinner (25.9 mm is what I measured).

Is this correct? (Sportspack has a thinner front antiroll bar) Seems counterintuitive to me, but the OP info appears to confirm this...