The plastic in-between the inner and outer parts serves to lock the two 1/2s together. And the safety part is in an accident the two 1/2s can become shorter, like will happen with the shifter column if so equipped and the expanded metal outer tube of the steering column
That is the safety aspect.
A non collapsible column (early As IIRC like early fords and I suspect Chevys too) were solid shafts of impalement :lol:
Here are 2 shifter shafts. One has been collapsed
Note the empty hole ( yellow arrow) and the non filled with plastic metal areas. Red circles
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Looks like 67 was the change over year
1967 Chevrolet Energy-Absorbing Steering Column.
56 Ford PU. How would you like top have that pointed at your chest in an head on collision
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