7/16in. Head Bolt Bushings- 20pcs.

The 7/16in. Head Bolt Bushings from Edelbrock are engineered insulators designed to isolate cylinder head bolts from direct aluminum-to-iron contact, a critical consideration in high-performance engine builds and restorations. These bushings serve as thermal and electrical barriers, preventing galvanic corrosion and heat transfer issues that commonly plague modern engine combinations where dissimilar metals meet under load. Whether you're assembling a stroker engine, installing an aluminum head on an iron block, or refreshing a classic engine with contemporary cylinder head technology, these bushings address a real mechanical problem that can lead to bolt failure and coolant leaks if overlooked.

Each bushing is precision-manufactured to fit 7/16-inch diameter fasteners—the standard bolt size on most small-block and big-block applications—and the 20-piece package covers a typical V8 engine configuration. Edelbrock's bushings are engineered from composite materials that withstand sustained engine temperatures and compression loads without degradation, maintaining electrical isolation that prevents unwanted current flow between dissimilar metals. The slight thickness and internal geometry of these bushings create a mechanical gap that reduces direct metal-to-metal contact while remaining thin enough to preserve correct bolt preload and clamping force, essential for maintaining proper head gasket compression and long-term seal integrity.

Experienced engine builders and serious weekend mechanics rely on these bushings when mixing materials—aluminum heads on cast-iron or ductile-iron blocks, aftermarket aluminum intake manifolds, or performance cylinder heads from different manufacturers. Installation is straightforward: simply slide the bushing onto the bolt before torquing it into the head or block. These bushings are particularly valuable in forced-induction builds, nitrous applications, and any engine where heat management and bolt reliability directly impact performance longevity. The 20-piece count ensures coverage for complete engine assembly, whether you're building a single engine or maintaining a shop's core inventory for regular customer work.