Results 1 - 48 of 126 The weight ratio on the car is improved over the stock KA24DE. head gasket can be used to increase your engine's compression ratio. Domestic Shelf Stock. Import Shelf Stock Along with a dedicated line of in-stock pistons, we specialize in the manufacturing of custom, high-end, forged KA24DE forged pistons for the 240SX are much stronger and are more Forged pistons feature a different manufacturing technique compared to stock pistons. CP pistons follow factory 9.0:1 compression ratios and require +.020" overbore.