S&S Cycle Power Packs — Harley-Davidson Electra Glide, Softail Heritage Classic, Electra Glide Classic (1955-2026)

S&S Cycle Power Packs are bolt-on big bore engine kits designed to transform stock Harley-Davidson engines with larger displacement and matched high-performance internals. Each kit combines 4.32-inch cylinders with a coordinated cam, cam plate, oil pump, and supporting components for reliable horsepower gains without custom machine work.

Features

• 4.32-inch big bore cylinders
• Matched high-performance cam and cam plate
• Upgraded oil pump included
• Complete cam chest package
• Designed for reliability and streetability

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 310-1051D
• Category: Engine Components / Piston Sets - Powersports
• Weight: 44.19 lb

Fitment

Fits Harley-Davidson models. Verify engine family and year with S&S Cycle before ordering to ensure compatibility with your specific platform.

Frequently Asked Questions

Do I need to have my engine machine work done, or is this bolt-on?

S&S Power Packs are designed as complete bolt-on kits. Most installations do not require extensive machine work if you're upgrading existing cylinders and heads.

Will I need a tuner after installation?

Yes — a fuel and ignition recalibration is strongly recommended to optimize performance and drivability with the larger displacement and new cam timing.

What's included in the kit?

The kit includes 4.32-inch cylinders, matched cam, cam plate, oil pump, and all necessary cam chest components to complete the installation.

How much horsepower will I gain?

Horsepower gain depends on your starting engine, heads, induction, and tune. S&S publishes dyno results for specific platform combinations — contact them for your engine type.