Crane's pushrod guideplates feature a significant increase in strength over stock designs. Their unique design provides a more rigid guide, reduces flexing, stabilizes the pushrod and reduces rocker arm ''wander''. Heat treated and carburized pushrods must be used with these guideplates, or premature pushrod wear and failure will occur. Cylinder head machining and screw-in rocker arm studs may be required to install these guideplates. 8/guideplates to a package.