‘’C’’ Servo Piston & Cover Kit to fit a 1966 HIGH PERFORMANCE C4 automatic transmission. This is the transmission that came in the factory equipped SHELBY GT-350 and other Hi-Po cars. Kits comes complete with all gaskets and seals (including a pan gasket) required for installation.The piston diameter is slightly larger than the standard unit providing an increase in surface area. This provides a firmer application of the intermediate band, or simply a quicker, cleaner, firmer 1-2 shift. The piston and cover unit will replace the standard ‘’A’’ unit without any modifications.CPC does not offer installation, assembly, adjustment assistance. If you require this type of assistance, please contact your local high performance transmission shop.