^^^ I'll expand on that a little.
The 65-66 GS with 401 used a steering column with a removable coupler so the column could be installed/removed with the engine in the car. There is little room between the exhaust manifold and the upper A-arm shaft. A steering shaft with the welded/pressed on flange is too large to clear that space during R&R, but I suppose it can be done by removing ex manifold or lifting the engine.
I believe all tilt columns, all engines, had the removable coupler?
1967 used a collapsible column and will not work in a 64-66.