AFAIK your frame uses the same rocker as the 04-07 Stumpjumper, in which case the rocker mentioned above would be perfect.
Loads better than the original Specialized part and gives you the option of either running 100mm or 130mm.
I run mine with a Pace RC40 which can be adjusted from 100-130, which makes my Stumpjumper very versatile indeed.
You might want a better rear shock too though, while you're at it.
Completed: 94 Stumpjumper w. M733; ; 92 Dave Yates 731 ; 97 Parkpre Pro-Elite ; Pace RC200 F6 ; Pace RC300; 82 Gios Super Record ; 97-8 De Rosa Giro D´Italia; ; Banani SPX Track bike ; 89 Alan/Mavic Cross Bike ; 05 Focus Cross Team ; 90 Look MI-80 all-Mavic ; 12 Focus Izalco Team/custom build ; 11 Focus Thunder Custom build
Projects : , Brouwer all-Mavic
Stripped : Pace RC303
Gone : GT Karakoram
Stayed in the family: Kuota Kharma, 04 Stumpjumper FSR
Ceased to be : Dynatech MT3, killed by corroded seatstays.