In GM TH350 and TH350C transmissions, the OE boost valve sleeve wears out from the reciprocation of the steel valve within the aluminum sleeve. Wear in the Reverse boost sleeve results in low line pressure, soft 1-2 and 2-3 shifts and/or Reverse engagement or shudder. Sonnax high performance boost valve kit 35754-01K incorporates a larger boost ratio, which increases line pressure and provides firmer shifts. It is also recommended for street/strip performance vehicles.

• Redesigned sleeve prevents sticking
• Larger boost ratio
• Drop-in Zip Valve™ parts install quickly and easily