Chevrolet Performance DRCE (Drag Racing Competition Engine) Big Blocks are the foundation of many of the most powerful Pro Stock Drag Racing engines. Developed specifically with 500-cubic-inch Pro Stock engines in mind, the DRCE family of engine blocks is the latest evolution of Pro Stock engine design. In order to build optimum performance, DRCE blocks have bore spacing that allows for the preferred big bore/short stroke crankshaft combination. The camshaft has been raised & the distributor moved. The big bore design unshrouds the heads, which means bigger valves can be used. The result is maximized air/fuel mixtures. DRCE blocks are solid without lifter or head bolt holes so any GM big block cylinder heads may be used, and blocks are gray iron or compacted graphite (an extremely strong material that helps combat bore distortion & crank deflection under stress).