Replacement 8-1/4" flywheel assembly for 116" engines with 4-5/8" stroke in 1999 - ' 02 Harley-Davidson® big twin models. These flywheels come assembled and balanced with connecting rods. While an S&S flywheel assembly can be used to replace the stock Harley-Davidson® flywheel assembly, individual S&S flywheel components cannot be used as stock replacement parts to rebuild stock Harley-Davidson® flywheels. The stock crankpin in a Twin Cam 88® or Twin Cam 96™ engine is 1.671" in diameter, while the S&S crankpin diameter is 1.500". S&S engineers decided to use a slightly smaller crankpin in order to allow the use of replaceable bearing races in the lower end of the connecting rods. In addition, the smaller crankpin size reduces the weight of the connecting rods, while avoiding clearance problems often encountered with increased flywheel stroke. Our experience with nitro burning drag race engines has shown that 1.500" diameter crankpins have more than enough strength to handle the most demanding performance applications.