I have found the following three to be the big steering slack offenders.

First, the idler arm pivot bushings. Look on the front outer end of the passenger frame rail exactly opposite the steering gear box. Lay under the front while a helper turns the wheel back and forth over about half a turn each way. I'll bet you see the idler arm pivot shaft wobble in the housing by several mm. This puts steering slop between the two front wheels. The dside wheel stays true to the steering wheel, and the pside wheel flops slightly as it goes from slight right to slight left turn. The pside wheel can also shimmy at speed due to the slop. Pside tire may show a lot of outer edge wear. Pretty cheap fix, but the fix usually doesn't last long with larger tires and heavy banging offroad.

Second common slop source is the adjustable gear lash in the steering gear box. There's a screwdriver-slotted stud with a locknut on top of the top cover of the steering gear box. I find the easiest way to adjust it is to make sure the front wheels are dead straight ahead, loosen the locknut, and gradually tighten the adjusting stud while twiddling the steering shaft with the other hand and feeling the slop in the steering shaft diminish. Test drive and see if you got it too tight, which is evidenced by a reluctance of the steering wheel to return to center coming out of a turn. If too tight, loosen the adj. stud about 1/16-1/8 turn at a time, retesting each time for loose enough to self center.

Third source is the pitmann arm ball-stud end wear. Pitmann arm is on the shaft coming out of the bottom of the steering gear box. Two tests. Mk1 eyeball as the steering is twiddled right-left by a helper, looking for slop in the ballstud/socket fit. You'll see the arm move slightly before the stud moves. Second test is to compress the stud into the socket with a big (BIG) pair of crescent pliers, and measure end of stud to bottom of socket housing distance. Remove pliers and remeasure distance. Any difference over .5-1mm means the pitmann arm joint is worn out. Replace the pitmann arm.

Fourth, Check the center link ends and tie rod ends for the same kind of wear as the pitmann arm.

Fifth, make sure the wheel bearings have no slop. The steering move the wheel spindle, and any bearing slop feels like steering slop. Jack up the front and vigorously wiggle the tire, holding top and bottom. Should be no wiggle slop felt.