RAW CASTING PER 356-T6 ALUMINUM ALLOY QQ-A-601; ANODIZE PER MIL-A-8625 TYPE 2 CLASS 2 AND CHEM FILM PER MIL-C-5541 TYPE 1 CLASS 2 ALL REMACHINED AREAS; CENTER HOLE 4.500 IN. O.D. 2.000 IN. I.D; 1.053 IN. OVERALL DP; 8 MTG HOLES 0.285 IN. DIA AND 2 HOLES 0.520 IN. DIA CSK TWO PLACES 2.938 IN. FROM CENTER; PART OF HYDRAULIC SHIFT GEAR