COIL ONLY SET, XR-1A HI-O

"4-Pattern" camshafts optimize valve events based on runner length, increasing area under the curve and high RPM stability. Designed to accommodate different runner lengths in conventional V8 intake manifolds, preventing valves from closing incorrectly. This technology, adapted from NASCAR, improves air/fuel ratio per cylinder, potentially adding 5-20+ horsepower and 1000+ RPM over other hydraulic rollers. CNC-machined from steel billet cores with cast iron distributor drive gears, featuring a tight lobe separation for performance and sound. Recommended in highly modified 420+ c.i. stroker applications with higher compression. 3500+ Stall.