I don't believe there's a keyway. I've only worked on the 68-70 columns, but I believe they are really similar. I can see two possibilities.
1. The column is fine, but it's installed too far forward (under-dash bracket)
2. The column's main center shaft has "telescoped".
For #1, I suggest you loosen (just a little) the bolts at the base of the column, where the column bracket attaches to under the dash (3 nuts or bolts), and where the column itself attaches to that bracket (4 bolts). Then, from inside the car, pull the steering towards yourself & then re-tighten. Does that give you enough clearance at the shaft/gear box?
For #2 (the more likely problem), it's a bigger job. The main, center shaft of the column "telescopes" like an antennae on a radio. The bottom part is solid (inner) & the top half (outer-which the solid part slides into) is hollow. The inner/outer parts of the center shaft are held in place by two plastic "shear pins" which can break easily. Those can be repaired/replaced, but requires taking the column out & disassembling it. It'd be tough to do in the car, but to be sure it's still the right length, you'd need the measurement of the length of that center shaft. That's the distance from the nut holding the steering wheel on to the tip of the "South end" of the shaft in the engine compartment.
I don't recommend it, but you "can" just pound that center shaft back up into the outer/upper/hollow shaft & let the steering box/shaft coupler hold the shaft at it's correct length. If you do cut this corner, I HIGHLY recommend that you add one of those weird spring clamps that holds the upper cover of the steering coupler on. Otherwise, it's just a tiny pin holding your steering shaft at the right length.
NOTE - don't hit the shaft with a hammer before you verify for sure that it has "telescoped" outwards. If it's already at the correct length, hammering on the end will break the little plastic sheer pins.