WISECO 3 3/4" BIG BORE PISTON KITS FOR EVOLUTION BIG TWIN | Big Twin | Dyna | FX | FXR | Softail | Touring

Piston kits, 3.740" Big Bore piston kit for stock stroke

These piston kits will convert your 1340 Evolution Big Twin motor to a 93.4CI (1530CC) Big Bore with stock stroke. Must be used in combination with a set of 3.740" bore cylinders. No cylinder head modification or re-balancing of the crankshaft required, just have your crankcase bored to the spigot size of these big bore cylinders. Compression ratio is 9.5:1 when using the stock Harley cylinder heads. Kit includes a pair of Wiseco forged pistons, Hastings piston rings, wrist pins and piston pin clips. Top end gasket kit for your year motorcycle must be ordered separately.

Note: These kits are designed for use with 1984-1989 and 1996-1999 stock crankcases or any S&S, Delkron or S.T.D. crankcase. Due to a weaker construction of the stock 1990-1995 crankcases the use of these is not recommended they should be replaced with S&S, Delkron or S.T.D. crankcases.