GM Powerglides used for drag racing generate higher line pressure than the OE servo piston can withstand. At pressures over 200 psi, the OE piston can crack, resulting in transmission failure. Sonnax servo cover kit 28821-06K works with Sonnax piston kits 28821-01K or 28821-02K to improve transmission performance and durability under high-pressure conditions.

• Lightweight, billet aluminum cover replaces heavy, cast-iron OE cover
• Easy to install, no case modifications required