Sixt5,
Can I assume you took a Manual steering car, and added Power Steering without changing the Steering Box??
If So, then you added the Advantage/Disavantage of the Gear in the Box to your Steering.
The Steering Boxes on these early Mustangs used a 4 Turn Box for Power Steering, and a 5 Turn on the Manual Cars.
Turn equates into Gear Ratio, the Ablility to use leverage.
A 4 Turn Box has less leverage, a 5 turn has more.
The 4 Turns were used on the PS Cars as the Leverage was not needed with the Hydraulics to push, pull on the steering link to achieve turning.
5 turn boxes were used to achieve turning, simply because the extra gear was necessary, unless you were a upper body builder.
So, to get to my point, you may have a 5 turn box, using with Power Steering (As we call it SUPER Power Steering), this will give you steering you can use your little finger to turn the car.
Dan
www.chockostangclassicmustang.com