NoneUnlock true street-and-strip flexibility with our C4 Overdrive Unit - engineered for extreme horsepower builds and everyday driveability. This bolt-on overdrive system transforms your existing C4 transmission into a dual-purpose powerhouse, giving you freeway-friendly cruising AND track-winning gearing at the push of a button. Why You Need ThisHigh rear-end gears are great for performance… until you hit the freeway. Running 4.30 diff gears at 110 km/h typically means your engine is screaming at ~3500 RPM.Flip the switch on our overdrive, and you instantly drop to ~1800 RPM at the same speed.Cooler temps. Quieter cruising. Better fuel economy. Longer engine life. Keep your aggressive gears for the track - then cruise home like a stocker.Who It’s ForDrag racersStreet/strip carsWeekend cruisersAnyone wanting big-gear acceleration AND highway comfort Whether you're hauling down the strip with 1,800+ HP or simply want lower RPMs on long drives, this overdrive unit gives you the best of both worlds.Key BenefitsBolt-On Overdrive for C4 TransmissionsElectronic toggle switch for instant ratio changeUltra-efficient — less than 1 HP loss per 400 HPHandles up to 2000 horsepower20-28% fuel mileage improvementDramatically reduces engine wearCruise faster, lower RPM, less heatPerfect for high-ratio gear setups (4.10, 4.30, 4.
