It could be dry (no lube in it), or it could have seized bearings in it. Or either/both of the two adjustments could be set too tight. The adjustments have to be done correctly, and in the correct order as described
here.
24:1 is the stock ratio. It's easy, but too damn slow; about 76.7 turns lock-to-lock (okeh, 5-3/4" turns. Still too much).
16:1 is the fast ratio available as an option from '65-'68. Just 3-1/2 turns lock-to-lock, but too damn stiff/difficult at slow speeds. Fine for certain kinds of competition driving, but out on regular roads it makes parking the car a pain in the nuts even with small, skinny tires and a lightweight aluminum 225 engine—a worse pain in the nuts (arms/shoulders) with bigger tires and a heavier engine. Efficiently saps all the fun out of driving the car.
20:1 is perfect. 4-1/2 turns lock-to-lock, not too hard to steer; a real joy to drive. They all should have come with this ratio, as the '60-'61 A-bodies did. 20:1 was not offered as original equipment when the cars were built, but available last I checked as an aftermarket worm assembly for the original Chrysler steering box, or as a complete rebuilt box from the specialists (Steer & Gear and/or Firm Feel).