[32phil]

The problem may be with the locking pin itself. That's the part that slides up & down inside the drop. The lock cylinder moves the pin in & out (or up & down depending on the year)only. If the pin is cruddy it will stick and cause the lock cylinder to feel like it does not work. If I remember correctly you can partially lube the pin from outside near where the drop bolts to the dash. You can see more of it if you take the two bolts out that hold the column to the bottom of the dash. You may have to loosen the 3 bolts that hold the steering box to the frame. If you take the switch box off the back you may be able to see more of the mechanism. Do what Charlie said again, this time spray the Chevy out of everything while you turn the key and watch the pin go up & down. Then take two aspirin and call me in the morning. Also,I can cut a key by code if you need one.