These forged 3-7/8" big bore pistons convert HD® Twin Cam® 88® and Twin Cam 88B® engines 95", and are compatible with stock or S&S® Super Stock® cylinder heads in. A 5.3cc pop up dome provides a slight compression increase. Piston weight is virtually identical to that of stock pistons in 88" motors, so rebalancing the stock flywheels is not necessary. +.010" bore.