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 that pair 4.32" cylinders with matched cams, cam plates, and oil pumps to deliver significant horsepower gains without a full engine rebuild. Designed for Harley-Davidson engines seeking reliable performance on a realistic budget.

Features

• 4.32" big-bore cylinders
• Matched high-performance cam and cam plate
• Integrated oil pump upgrade
• Complete cam chest package
• Bolt-on installation

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 310-1056C
• Category: Engine Components / Piston Sets - Powersports
• Weight: 44.19 lb

Fitment

Fits Harley-Davidson models. Verify specific model year and engine family compatibility with S&S or your dealer before ordering.

Frequently Asked Questions

What horsepower gain should I expect?

Gains depend on your engine's starting displacement and tune. S&S provides dyno results by engine family — contact S&S or check their website for your specific model.

Do I need to retune my fuel injection?

Yes. A power pack changes air and fuel flow, so fuel mapping adjustments are required for optimal performance and reliability.

Can a shop install this, or is it a full engine tear-down?

Installation complexity varies by model. Some kits are bolt-on to the cam chest; others require partial engine work. Consult S&S documentation and a qualified shop before ordering.

Is this the same as a complete engine rebuild?

No — Power Packs upgrade the top end and breathing. A full rebuild would also involve bottom-end machine work, pistons, and rings.