93 is when the shifting logic went electronic, but I think the electronic speedometer was a couple years before that.
It's my understanding the tailshaft (4 bolt) can be changed out from an earlier mechanical speedometer tranny, even a 350, to install the mechanical speedometer gear.
~ Victor
1941 3/4-Ton Pickup (in process). Read about it
in the DITY Gallery1955 Grumman Kurbside "Doughboy" 235/3 on tree w/ OD
1957 3100 - moved on
1959 C4500 Short Bus "Magic Bus" - moved on
1959 G3800 1 Ton Dually "Chief" - moved on
1958 C4400 Viking "Thor" ~
moved on to fellow Bolter 
