Topic: CB750 spark advancer differences - can you tell one from another ?

[greenjeans]

Working on a 75 CB750K.    Using a lot of spare parts accumulated throughout the years.

Down to the spark advancer - I seem to recall that the earlier ones were different than the later ones - but how ?

Is there a way to tell the difference ?   Is there a number or mark on them that would give me a hint as to which is which ? 

Would I even really need to worry about using an earlier one vs a later one ?  Thanks in advance 

[Dream750]

There were only two advancers used on the 1969-76 750 (K) engines and the visual differences make them easy to spot:
 
The advancer on the left is the early K0-K2 type, made by Hitachi, PN: 30205-003-005
 
The advancer on the right is the late K3-K6 type, made by TEC, PN: 30220-300-154
 
The TEC superseded the Hitachi and can be used in all K0-K6 engines according to American Honda.

[Dream750]

GJ, were you able to see the advancer differences? If you need better quality pics let me know.