So here's where my experience differed. I looked on the coupler for the upper pin as labelled in the FSM for 1971 Dodge vehicles - didn't find it.

Instead, I took out the bottom pin, the one that goes through the coupler off-center and holds itself to the steering gear input shaft by sitting in the groove on the input shaft ifself. This allowed me to remove the column from the gear once I removed the column mounting flange from the firewall.

To reinstall, I lined up the non-splined area on the input shaft to the non-splined area in the coupler, and pushed down on the column to slide the coupler down. It did not go on easily, I can tell you that much.

Maybe my column coupler was installed incorrectly before I got the car? It's been this way since I've had it.