Std 3-7/8in. Bore, Forged 106ci Stroker Pistons. Fits Twin Cam 1999-2006 with S&S 4-1/2in. Stroker Flywheel

* These forged 3-7/8" bore stroker pistons for 1999-2006 Twin Cam are required for the S&S 106" stock bore stroker kit with 4-1/2" stroke flywheels.

* Flat Top Pistons. 3.875" Bore & 4-1/2" Stroke

* 10.1:1 Compression Ratio with Stock 85cc Heads.

* 9.8:1 Compression Ratio with S&S 89cc Heads # SS106-3240.

* They are compatible with stock or S&S Super Stock cylinder heads.

* Stock 88" cylinders may be bored to fit these pistons or purchase # DAY-88461

Tech Tips:-

* Follow Ring End Gap & Piston to Cylinder Clearances as per the supplied Manufacturers Instructions.

* Pull the engine down first & measure the existing bore to determine if oversize pistons are required PRIOR to purchase, we do not take back piston kits. The onus is on the assembling technician to validate the cylinders & required pistons.