The BB-1 rectangular port head has a 280 cc intake port and a 119 cc combustion chamber, but may be angle milled to 108 cc or angle machined to 98 cc. The BB-1 is designed for a 396 to 502 engine with a flat tappet or hydraulic cam. Most marine applications use this head for torque and throttle response. The BB-1 also comes completely CNCported. The 305 cc intake port flows over 370 cfm and has maximum port velocity. The BB-1 cylinder heads accept standard pistons, intake manifolds, and rocker arms. The exhaust ports are raised .600 higher than stock, and the valve cover rails are now raised to assure no oil leakage. **Heads are being sold as pairs and bare**