There is also a worm gear bearing adjustment...removes play from the worm gear bearings and puts a slight pre-load on those bearings (which is necessary). Once that is done, as Jerry said get the worm and sector gear to the center point and adjust that so there's the proper resistance there. Resistance at the center point will be the greatest and will diminish as the sector gear is moved to either right or left. An inch pound torque wrench is a really good way to determine this. I'd check both worm gear and sector gear adjustment. It sounds to me like there's a possibility neither was adjusted when your steering box was "rebuilt." Here is an explanation from the 2nd series 1955 manual: https://chevy.oldcarmanualproject.com/shop/1955truck2/55ctsm0904.htm

Good luck.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end