These billet main bearing caps are machined from 1010 cold drawn steel. The outer bolt holes angle outward toward the oil pan rails. This splayed bolt design improves reliability in highly stressed racing engines by tying the cap to the strongest part of the block. It also reduces distortion of the main bearing bores by increasing the cap's resistance to closing up under high loads. Billet steel main caps are designed for blocks with 2.45" main bearings. The Chevy Bow Tie is laser etched on top of the cap. Technical Notes: See the Chevy Power manual for machining instructions when installing splayed bolt caps on blocks originally equipped with two-bolt or production-type four-bolt caps.