69 440 six pack had the same part number in the parts book. From my experience of taking original motors apart of both years, the FORGING number on both cranks was 2208160 ( from my memory) I have found that same number in a couple of other motors, on 69-70 only. I believe they chose that forging to shot peen for the 6 pack motors. I bet that same shot peened crank found its way into a few non six pack motors as well.