Sonnax super hold servo kit K665703-1 for GM 200, 200-4R, 200C units features a 17% greater apply area than the Grand National servo. Its pin is longer than the longest OE pin, allowing for a full range of adjustment. The optional parts include a shim, spring and spacer which, when combined with OE springs, result in a variety of shift tuning capabilities. Altogether, the level of customization in this kit makes it ideal for high-performance street applications as well as all-out racing.
Overall sealing characteristics have been improved throughout the servo, which features an O-ring to seal the piston to pin. This O-ring prevents cross leakage between the apply and release side of the piston, ensuring all apply pressure gets to the piston for solid shifts.