Where can I get a power steering gearbox for a 1956 Dodge custom Royal
Horizontal steering columns allow users to steer using custom motoized telescroping steering columns.
You cannot turn the wheel while parked. Try turning on the car, keeping it in park, and Turning the wheel if there is a lot of force needed to turn it, check the belt and fluid levels.
on the steering wheel
you don't because it's a federal offense to remove a steering wheel that has a stock air bag in it
It is very hard to turn the steering wheel and/or a whining or squealing noise when you turn the steering wheel.
If you have plenty of fluid it could be the power steering pump itself going bad or it could be the rack and pinion assembly.
on the right side of the steering wheel
Most vehicular steering wheels are generally made of plastic over a steel "frame" or core. Certainly there are many custom or racing variations.
Under the dash on the left of the steering column
Momo Steering wheels are made in Italy. They also produce all the parts and pieces you would need to change your steering wheel out. Momo also is a top maker of custom wheels and rims made from a light alloy.
70's nova's had a tilt wheel as an option so if you could find one that would be the best trick but you can get a custom steering column for it from ididot.com.