Help Identifying cast aluminum Hemi heads

Trying to Identify heads off of a stage 2 KB, there is a # P4120960 near the center of the spring area, and off towards the side of spring area is a four letter symbol made up of the letters DP with CD below forming a square and the tail of the P runs top to bottom of the symbol. Are these early Dart fuel heads from the 70's? Would post pictures but I am slightly computer challenged. Any help is appreciated.