No. The 1973 motor is set up for the drives that run from 1973 -1977 on the 115 and 85 and from 1973 through 1976 on the 135. Everything to do with shifting outside of the gearcase is mechanical on those models.
There are many lower units around for that series. They were very good systems and they don't get hurt easily. I still have three extras in the shed including a brand new one that has never been used.
