The B1 Mopar is designed for the serious Chrysler B big block racers and is easily capable of flowing over 400 cfm. This head works well on a 440-540 cu in engine with at least 13.0 to 1 compression and up to 7500 rpm. The deck is very thick and may be used with nitrous. The B1 Mopar requires some special parts such as pistons, rocker system, intake manifold, and valve covers. This head uses standard headers and a B block.