[SRT Engineers]

j-rho: I'd like to know the front and rear spring rate differences between the 2003-2006 cars and the 2008. If the 2008 rates are appreciably higher, would also like to know if these parts could be made to supercede the old in the factory parts books. Such that if my stock coilovers "disappeared" I could get the new parts as legitimate stock replacements at the dealer.

2003-2006 SRT-10:
Front: 200 lb/in
Rear: 500 lb/in
Front Anti-roll Bar: 27mm Hollow
Rear Anti-roll Bar: 27mm Hollow
Michelin PS1 Tires

2008 SRT-10:
Front: 210 lb/in
Rear: 525 lb/in
Front Anti-roll Bar: 27mm Hollow
Front Anti-roll Bar: 27mm Solid
Michelin PS2 Tires

2008 ACR:
Front: 514 lb/in
Rear: 1085 lb/in
Front Anti-roll Bar: 27mm Solid
Rear Anti-roll Bar: 27mm Solid
Michelin PSC Tires

Each of the Viper models are tuned specifically for:
Tires
Aerodynamics
Weights
Horsepower
Wheel Alignment
Differential Operation
Etc.

So to summarize, we would not recommend simply substituting 2008 coilovers on a 2006 model. In this specific case we would recommend at least the change of tires and rear anti-roll bar.