very large intake and exhaust valves sitting in a small quench style combustion chamber. Exhaust valves were sodium-filled to aid cooling. Valve springs were dual units with an inner and outer spring to minimize harmonic resonance at high RPM. The heads feature steel spring seats, screw-in rocker studs, pushrod guide plates to aid in pushrod stability at high RPMs, and adjustable rocker arms. Fuel was provided by a Holley manual choke carburetor. The taller intake required a thinner spacer. Ford used a phenolic spacer that incorporated an aluminum tube for the PCV hose and also helped isolate the carburetor from the heat of the intake. Ignition was handled by a dual point distributor firing unique AF 32 Autolite spark plugs specified because of their smaller size ( wrench vs. wrench) so as to fit within the tight confines of the combustion chamber alongside the very large valves. The motor produces a unique sound as a result of its solid-lifter configuration. At idle, properly tuned, the engine produced a significant amount of 'chatter' noise. The power output was at 5,200 RPM with maximum torque of at 4300 RPM. It had a 6,150 RPM limit. The Boss 302 engine competes well with other high performance 'small blocks', such as the Chevy 302, the Chrysler 340, and the AMC 360. The "Boss" in the Boss 302's name came from original designer Larry Shinoda's reference to Bunkie Knudsen, the CEO at Ford and an outspoken proponent of the car's development, who told his designers, "I want to design a car that's the coolest Mustang out there. I don't want somebody else's name on it, like a Shelby." Boss 302 is the name of the car (the engine is the 302 H.O.) but it also became popular to call this specific engine the Boss 302. This engine was also optional in the Mercury Cougar Eliminator, with a total of 169 produced in 1969 and 469 assembled in 1970. New Boss 302 (2007-) The new Boss 302 engine was unveiled in the 2006 SEMA show. In 2007, Ford Racing began marketing new crate engines using the "Boss 302" moniker with displacements between that are rated from . The double overhead cam, variable valve timing Ford Modular "Coyote-Boss" engine is also marketed as a crate engine by Ford Racing. Additional Information The Boss 302 engine may be confused with the 302 Cleveland Ford small block engine, which