GM factory-installed directional-signal assembly option (Regular Production Option) in 1954 - no
First integrated-into the steering column GM truck accessory directional-signal assembly in 1954 - yes
The steering-column/steering-assembly is different 54/55 vs 47-53, but might the 54/55 steering-column/steering assembly easily work in the earlier truck? Maybe someone knows if the steering components match up - the differences might only be in the outer column (and the steering wheel)?
Pages 1-3 of these installation illustration show/explain how the wiring from the switch in the cup is routed into a hole in the steering column, down the steering column, and out a hole in the steering column under the dash.
A cup covers the switch/wires and the hole in the column under the steering wheel; and, a metal cover is screwed over the lower-down hole in the steering column where the wires come out of the column under the dash. This allows a "neat" installation of the accessory turn-signal switch/cover - no wires running on the outside of the steering column.
This is why I think it could be possible that the 54/55 steering-column/steering-box might work in an earlier truck. There is a different 54/55 column-to-dash clamp/rubber, but the 54/55 dash is different from 47-53. The 54/55 steering column might fit in a 47-53 truck/cab with the 47-53 steering-column-to-dash clamp/rubber? But as I posted above, the 54/55 steering wheel would have to be used (and, the 54/55 horn button).
