An S&S 103" 3-5/8" Sidewinder big bore stroker kit is an economical route to a larger displacement engine. This kit contains nearly everying needed to take a stock 74" or 80" HD® shovelhead engine up to 103" displacement. This kit includes S&S 3-5/8" bore high tensile cast iron Sidewinder® cylinders and forged pistons with wristpin and rings, a 5" stroke small diameter dynamically balanced S&S flywheel assembly, complete with S&S heavy duty connecting rods and mainshafts, S&S stainless steel head bolts, base nut, S&S adjustable chromoly steel pushrods, head gaskets, base gaskets, exhaust gaskets, and an S&S heavy duty top motor mount. Compression is 9.7:1
Crankcases must be bored to accept larger 3-5/8" bore cylinders
IMPORTANT: 1977-’89 style pinion gears, spacer, and nut are required when installing S&S flywheel assemblies. For installation in 1990-’99 or scratch built engines, order
S&S Pinion Shaft Conversion Kit 33-4148
Not legal for sale or use on CA or EPA pollution controlled vehicles 1978 and later.
Cylinders in this kit are longer than stock - a longer manifold must be purchased separately
Frame clearancing may be required due to the longer than stock cylinders in this kit.