Ford Racing is following the Boss 302 block released in 2006 with the new Boss 351 block, featuring performance and packaging that will accommodate displacements from 351 to over 460 cubic inches.
The Boss 351 block is based on Windsor 351 architecture with a Cleveland sized 2.75-inch main bearing journal. Available in two deck heights, 9.2-inch and 9.5-inch, the Boss 351 is designed for performance with 4-bolt main caps and screw-in freeze plugs. Technological improvements such as splayed main bolts, siamese bores with engineered coolant cross-drilling, front cross-over lifter oiling, and diesel-grade iron with 41,000 psi tensile strength separate the new Boss 351 from both stock and aftermarket blocks.
Max stroke is up to 4.25 inches, depending on crankshaft manufacturer with max bore size topping out at 4.125 inches with coolant cross drilling. A non cross-drilled block with increased bore capacity will be available by the end of the year.
The new Boss 351 is built from all-new tooling and incorporates technical developments compiled by Ford Racing engineers and racers. “Whether they’re building an all-out drag racing engine or looking for a street performer, the Boss 351 block meets the needs of all Ford 351 enthusiasts at a price comparable with a performance-prepped stock block,” said Ford Racing Director Brian Wolfe.
Suggested retail price for the Boss 351 block is $1,999. A Boss 351-based crate engine with 427cid is expected to be available by the fourth quarter of 2009.