We've expanded our line of SBC single plane manifolds to include a new 13 degree configuration. This proven design, already available in a 23 degree configuration, features pre-cast bungs for either fuel injection or nitrous. The Wilson Manifolds port design is ready for direct bolt-on performance or have our technicians prepare your intake with a full competition port/polish. Cast with standard 4150 carburetor flange. Additional head configurations can be fitted with minor modifications.