Ford Racing BOSS 351 Cylinder Block 9.5inch Deck

Cast from diesel grade iron, this Ford Racing BOSS 351 cylinder block is built for serious projects requiring a 9.5-inch deck height. Ford Racing engineers updated the legendary BOSS 302 and 351 blocks using advanced technology from both production and racing worlds. This block preserves many dimensions and features from the original 289-351 Windsor style engines, making it a compatible replacement for a wide range of vehicles that used those powerplants.

The BOSS block's strength is significantly improved over original Ford OE blocks due to added material in critical areas. It's designed with a 4.125-inch bore capacity, with a finished bore range of 3.990-3.995 inches. For optimal performance and reliability, it's recommended to use special length 1/2-inch head bolts or head studs, along with specific cylinder heads like the M-6049-X306/307/Z304DA series. While designed to work with stock-type timing covers, the M-6059-D351 timing cover is recommended. The block retains the original clutch cross shaft pivot hole, original oil filter location, original motor mount boss locations, and the original bell housing pattern, simplifying installation in many applications.

This block is the foundation for many high-performance crate engines and has a proven track record on both the street and the track. It weighs approximately 205 lbs. A service replacement plug and dowel kit, M-6026-A, is available separately and includes O-ring threaded plugs for oil galleys, water drains, and core holes, along with dowels for the front cover, clutch housing, and cylinder heads. Please note this block is not CARB approved and cannot be shipped to California.