S&S CYCLE V124 Long Block Engine — 124 in³, 4-1/8" bore, 4-5/8" stroke, Black – 84-86 Big Twin, 84-95 Touring, 85-89, 91, 93, 98-99 Softail, 91, 94-95 Dyna, 85-94 FXR, 99 CVO

Built to fit '84-'99 Evolution Big Twin and '70-'99 custom chassis with alternator-style primary, this long block renews the rotating assembly and top end for high-performance applications.

Specially machined cylinder heads accept a stock-length manifold and allow use of your existing carburetor with re-jetting; crank and case are machined for a crank position sensor for EFI compatibility.

The assembly includes premium cylinder heads, high-performance valve springs, hardened rocker arms, a performance cam, a three-piece flywheel assembly, a 1.671" diameter crankpin, 0.927" wristpins, a high-volume high-pressure oil pump, electric compression releases, and high-strength pistons.

Made in the U.S., the unit is designed to bolt into stock or aftermarket EFI, carburetor, or air-cleaner setups and will require a performance ignition and performance carburetor for best results.

Includes gloss engine covers; professional installation recommended.