Both the early cast aluminum and late molded rubber versions of the 4L80E Direct Clutch Piston fall short in performance applications. The pistons have a narrow work surface applying the clutch pack and lack positive seating for the direct clutch apply/release springs. This kit includes a modified OEM TH400 Direct Clutch Piston which provides positive seating for the apply/release springs and a wide work surface which improves the distribution of apply force transmitted to the clutch pack. The revised design eliminates the use of the direct clutch cushion plate and allows the additional installation of one additional clutch and steel plate, increasing the clutch pack count from five to six plates. The clutch housing will now accept six .090" standard thickness direct clutch friction plates and six .080" standard thickness direct clutch steel plates. Also included is a set of 16 high rate direct clutch apply/release springs which allow maximum pressure values in the direct clutch apply circuit to be obtaoned before the clutch pack applies, vastly improving shift quality and clutch pack capacity. Completing the package is an OEM TH400 stamp steel Apply/Release Spring Retainer, providing the user with everything neccesary to complete the installation.