for starters, you don't "steer" while standing still, nextly, you won't find any tires that will make it easy to turn the wheel of a 50s truck when not moving, it's the nature of the beast and why the steering wheel diameter is so much larger than on modern trucks .... but, radials of any size will make it much easier to turn the wheel when you have even a small momentum forward or back, the reason a wider tire may take a bit more effort to steer in motion is the steering geometry was designed for much narrower rims and tires, wider tires put too much leverage out beyond the ends of the spindle, particularly with the much wider than stock 7" rims .... the difference in the sizes [215/235] you're discussing shouldn't be noticeable
Bill
