In terms of parts compatibility, a lot of the internals are the same. In fact, the upper housings are the same as far as I am aware. In my column rebuild, I ended up using a combination of Jeep bearings (They borrowed the column design for some time) and Monte Carlo bearings.
As far as my understanding goes, the biggest difference on the columns is in shaft angles, splines, and lengths of the lower shaft parts.
1985 Pontiac Fiero 2M4