4-Pattern 253/263 IB H-Roller Cam SBC

Recommended in larger c.i. and high compression applications. 3500+ Stall. Fits '58-'02 262-400 c.i.d. Chevy Small Blocks. Upgraded valve train components and aftermarket cylinder heads required. WARNING: Camshaft Optimized for use with a Melanized or Nitrided distributor Gear. Not compatible with cast or Steel Gears without similar surface treatments. Failure to utilize the proper distributor Gear will void all warranties and/or return policies. 4-Pattern Optimize Valve Events Based on Runner Length Increases Area Under the Curve and High RPM Stability. To make the most power from your engine, you need to optimize the air ingested and captured by avoiding valves closing too soon or too late. Any conventional center layout single throttle body or carbureted V8 intake manifold features longer outboard runners and shorter inboard runners, meaning that each valve event should occur at a different moment. COMP Cams 4-Pattern Camshafts are the very first Series of cams designed to accommodate this difference in length and avoid valves closing at the wrong times. NASCAR teams have been using Camshafts designed this way for years, and using lessons learned along with them, COMP Cams has designed a Series of cams that optimizes valve events and features a large increase in both area under the curve and stability at high RPM.