Sonnax super hold servo kit 28821-09K is an all-in-one upgrade ideal for a competitive edge in GM Powerglide applications where racers are looking to reduce line pressure to free up horsepower. The kit's dual piston design features 30% more apply area to increase band apply force at your current line pressure or allow you to reduce line pressure by 20% to 30% while maintaining the same apply force.

Dual piston design for 30% more apply area
Spring counteracts pin bias effect up to 275 psi
Improved sealing throughout
Low-profile design ensure adequate clearance
6061 Anodized billet aluminum cover
Sonnax super hold servo kit 28821-09K is an all-in-one upgrade ideal for a competitive edge in GM Powerglide applications where racers are looking to reduce line pressure to free up horsepower. The kit's dual piston design features 30% more apply area to increase band apply force at your current line pressure or allow you to reduce line pressure by 20% to 30% while maintaining the same apply force.

Dual piston design for 30% more apply area
Spring counteracts pin bias effect up to 275 psi
Improved sealing throughout
Low-profile design ensure adequate clearance
6061 Anodized billet aluminum cover

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