8 3/4 question

I beg to differ with you guys.

There were four different 8 3/4" carriers which were used from 1957 through 1974.
The 1820657 carrier,which was used through 1964,and the 2070741 carrier,which replaced it,are both of the light-duty variety.The 2070742 carrier used a pinion with a 1 3/4" diameter,and was considered the heavy duty carrier until 1969,when it was replaced by the 2881489 carrier.The 2881489 carrier used a pinion with a tapered stem and was the heavy duty unit from 1969 on.The 489 carrier is the strongest of the lot......