[rick conrath]

I am a little confused here. When I check the part numbers and illustrations in my PET, the 964 and 993 share the same sprocket numbers,wwodruff key as well as dowel pins at least up until '95. Chain wheel # 901 105 546 02 appears to be used well back into the' 80's. So if I am backdating to 964, what year is the benchmark? My '97 sprocket assembly also shows dowel pins and the basic hardware setup as the earlier '89 c2. I can see no difference between the 993 and c2 other than the tensioner setup and hydraulic rocker arms. What benefit is there for me to backdate to 964 style?
Rick
'78 930