Okay, I was keeping this to myself, but it's time the cat was let out of the bag on this steering coupler adaptor.
The ORIGINAL EQUIPMENT adaptor is found on 1978-1988(?) Dodge Vans WITH MANUAL STEERING ONLY. The reason the adaptor was made was to limit the later columns to ONE design of column (Tilt or Non-tilt, doesn't matter, they fit the same), so Ma' standardized the van columns, and used the adaptor to build the manual steer vans.
It is also interesting to note that the STOCK unit also employs the MANUAL pot coupler, rather than the Flaming River/Firm Feel pieces, which use the POWER pot coupler.
In short, it's the LATER vans that use these, not the earlier (pre-'78 ) ones.
Mark.