Our MAGNUM line of cylinder heads for the big block Chevy are available in Oval Port designs with runner volumes of 265cc, 290cc, and 300cc or Rectangular Ports with 305cc, 315cc, 325cc, 335cc, 345cc, 357cc, 377cc and 385cc runners. All heads are made with A356 aluminum and are equipped with high quality components throughout. Component upgrades and different machining options are available to customize your AFR heads for your specific build.