A super servo is a sonnax oversize servo for the gm 2004r transmission .it has a larger apply area than the stocker.this produduces a firmer shift into 2nd and 3rd gear. a larger servo reduces the chances of a back to first 3/2 kickdown with hi powered engines and raises the clamping force applied to the band during 2nd gear operation. the sonnax design as welll as some others advocate deleting the cushion spring out that applies the servo.this is a poor reccomendation.We have developed a servo with a larger apply area than sonnax,tci,btoverdrive,pts etc.This is guaranteed .the od of our servo is 3.005 and uses a smaller o ring to accomplish proper cover to case sealing with the punched out diameter.This design allows the use of accumulator circuits(not deleted)with spring as well as the cushion springs and still they produce killer shift quality at all throttle angles and no part throttle bangs.here is a link to ours
www.CKPerformance.com