CAST IRON; 11.820 IN. DIA; 4 TANGS 1.855 IN. LG EQUALLY SPACED 90 DEG APART; 4 SLOTS 0.715 IN. LG EQUALLY SPACED 90 DEG APART; 12 NOTCHES 0.750 IN. LG EQUALLY SPACED 30 DEG APART; 4 POSITIONING HOLES 0.562 IN. DIA EQUALLY SPACED 90 DEG APART; 16 DRILLED HOLES 1.125 IN. DIA LOCATED IN INNER CIRCLE; 20 DEG PRESSURE ANGLE