Not many people in the Probe/Mx6 world know of Spec. Spec is a big name in the V8 world. Almost everyone I know with Camero SS's has a Spec Stage 3. I did a holding capacity comparison one time on the Spec's for the 4cyl and CM was a 70% over stock compared to a Spec's 210% over stock. Both of these were their Stage 1'sunkiedave said:better than clutch masters? CM seems like the big favorite pick.