The last time i heard something similar was on a Pontiac, and virtually the same scenario. The final cure was a second trip to the junkyard and a second box to solve the problem. The steering had a "hard spot" part of the way through a right turn. Only thing I could figure was it sat for so long in the junkyard in one position. Who knows? You should also check the rest of your steering components thoroughly. A bad steering damper or even a loose tie rod end can cause the same sort of issues.

Richard S.
88 Toy 4x4 Truck, 22RE, 3"BL, 5-Speed, Muds
Proud to be an American. Blessed to be a Texan!