The cam sprocket assy should NOT be washed in a degreasing solution ! The little dampers of the ignition advance unit are made of neoprene, and will get loose and finally work them self from the pin. If this happens, not only your engine will make a "clacking" noise but the ignition timing will change.
Furthermore, when heating the cylinder head in an oven (+/-150 deg Celsius +/- 300 degrees Fahrenheit), the bearings will come out easier, and new bearings will fit tighter in there housing.
btw, it's a pitty that the Honda305.com website is not active any more (and for me unreachable). Lot's of info there, also from me (before I started with the 450's 7 years ago, I was specialising for 20 years on the CB72/77 and dreams. I have a CB72 of every year these where build, starting from 1961 to 1967 plus a few CB77's and dreams.
As I recall, it should be a right-hand thread.
Yes, most are, but some are not, I have them both NOS (I recall that these were early)
CB72/77 hawk/superhawk sprocket with advancer
C72/77 dream sprocket with advancer
Early type C72/77 dream sprocket with advancer + weights for smoother running (360 degree engine)
CB72/77 thread which is right handed
C72/77 early advancer thread which is left handed
btw, sorry for all this info, miss the honda305.com.