Pulley Kit Serpentine Ford 347SR/JR 12% Red.

The Pulley Kit Serpentine Ford 347SR/JR 12% Red by KRC Power Steering is designed for high-performance Ford engine builds, particularly for 347 cubic-inch stroker and junior dragster applications. This serpentine pulley system replaces traditional V-belt arrangements with a streamlined single-belt design, reducing parasitic drag on the crankshaft while enhancing underhood aesthetics.

KRC's serpentine pulley configuration features a 12% underdrive ratio, which reduces alternator and water pump speeds relative to engine RPM—critical for minimizing belt-driven accessory losses on high-revving builds. The red anodized finish provides corrosion resistance and visual distinction in the engine bay, while the precision-machined aluminum construction ensures tight tolerances and long-term durability.

Builders of 347 Ford strokers—whether small-block Windsor derivatives or junior dragster engines—benefit most from this conversion, as the reduced accessory drag directly translates to measurable horsepower gains at the wheels. Installation requires basic mechanical competency and standard hand tools; most applications can be completed in 2–3 hours.