The other issue I'd be looking for is do you have the GM Starter Interlock / SAFETY switch installed (or installed correctly). I think you said you have a column switch - which leads me to think you're trying to use a "factory" style harness and electrical connections.
Here's the neutral safety switch -- it's not going to let you start the car if it's not wired correctly. It should look like this or something similar. Again - you may need to find a wiring diagram specifically for your situation.
