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

S&S Cycle Power Packs are high-performance piston sets engineered for Harley-Davidson engines to increase displacement and power output. Direct bolt-in replacement for stock pistons when paired with compatible cylinders and gasket kits.

Features

• Engine displacement increase
• Direct replacement piston set
• S&S Cycle engineering

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 310-1390A
• Category: Engine Components / Piston Sets - Powersports
• Weight: 44.19 lb

Fitment

Fits Harley-Davidson engines. Requires compatible cylinders and gasket kits for installation.

Frequently Asked Questions

Do I need new cylinders to use these pistons?

Yes — S&S Power Packs are designed to work with compatible S&S cylinders and gasket kits as a complete top-end upgrade.

Will these bolt directly into my stock cylinders?

No — these are engineered to pair with S&S-matched cylinders for proper fit and displacement gains.

What displacement increase should I expect?

Displacement gain depends on which S&S cylinder kit you pair with these pistons. Check the cylinder kit specs for your target displacement.

Do I need a tuner with this upgrade?

A fuel/air calibration is strongly recommended after installing a complete piston and cylinder upgrade to optimize power and ensure proper engine operation.