Ford Racing Engineers have designed the replacement for the legendary BOSS 302 and 351 blocks using the latest technology and manufacturing techniques from both the production and racing worlds. The BOSS block capability has been proven abound the world – both on the track and on the street. By preserving many of the dimensions and features from the original 289-351 blocks, the BOSS blocks are compatible as replacements for use in just about any vehicle that used aWindsor style engine. Cast from diesel grade iron and designed with added material in key areas, BOSS block strength is far superior to any Ford OE block ever produced. Requires special length 1/2" head bolts M-6065-BOSS or head studs M-6014-BOSS recommended with M-6049-X306/307/Z304DA heads. Designed to be compatible with the original 302 and 351W blocks. Designed to use stock type timing cover, timing Cover M-6059-D351 recommended; Designed to use stock type timing cover, timing Cover M-6059-D351 recommended; M-6026-A Service Replacement Plug and Dowel Kit available separately; includes O-ring threaded plugs, black anodized aluminum plugs with Buna "O" rings for the oil galleys, water drains and core holes, and dowels for front cover, clutch housing and cylinder heads. Retains clutch cross shaft pivot hole; Original Style oil filter location; Original motor mount boss locations; Original bell housing pattern; Weighs approximately 205 lbs.; Great price and value; The foundation for 9.5" deck projects. Proven performance - used in Ford Racing high performance crate engines, a proven winner out of the crate and thousands of laps before rebuild.