A diagram of the 1971 Chevy Nova steering column would include the ignition and the shifter information along with the steering column itself. This type of diagram is often found in the Chilton's manual for the year and model.
Probably the steering gear.
The steering wheel cannot be bypassed to rewire turn signals in a 1989 Chevy Corsica. The switch for the wires is in the steering column. If the steering wheel were bypassed, the wires would not be connected to the switch.
It would naturally ground through the steering box, to the frame.
What it would cost to fix your steering column depends on what is wrong with it and you did not tell us. The tilt steering column in my 1989 GMC Suburban became loose in the tilt mechanism. I was quoted as much as $125.00 to fix it, but I shopped around and got it repaired for $60.00. Unless your steering column has the same problem that number is probably useless. I would suggest you call several shops and get a quite to fix it.
You have to replace the entire steering column. It is not loose, the lock is broken on your column height adjuster.
There are 4 bolts at the bottom of the steering column that tend to get loose after entering and exiting your vehicle. Pulling your self up on the steering wheel puts stress the steering column and causes it to become loose. If you do not correct the problem fast by tightening the bolts you will have to replace the entire steering column.. -Henry's locksmith and steering column repair
on the steering column beneath steering wheel
You have to change the steering box and find another vehicle that year to get all the brackets and pump unit. You might be able to order those items from GM or some after market purveyor.
This is a part you would want to purchase at a auto salvage yard. Buying it from GM would cost plenty. Call around your area for prices.
Assuming this is also called the neutral/park safety switch, it would be found on the lower portion of the steering column (column shift) or in the console (floor shift). You will not find it on the transmission itself.
The bed size is 6.5' of a dimension of 78x9x5 would fit a Chevy 1990 pickup.