They have splines but no master spline that would only allow the wheel to go on in only one position. You can install the wheel in any position. I would advise to to center you steering box by first turning it to the lock in one direction. Then turn and count the revolutions to the stop in the other direction. Next turn back exaclty half the total number of turns. This will "clock" the steering box. Install your wheel in the upright position. THEN take the car to get the front end aligned so the wheel is again straight up.
