Re: part swap compadibility
If they are both the same series 55, that is, both single carb engines, then the ignition components are interchangeable as long as they are both the same ignition type. That is, both magneto ignition or both battery and points ignition.Also, I am not certain which 55s used a version of Magna Power electronic. SO if the earlier engins e is not (most likely) and the later engine is Magna power ignition, then the whole ignition system must be swapped as the coils are different.