Welcome!
You do NOT need a rack and pinion.
You do not need new leaf springs.
What you do need to do is thoroughly inspect your front suspension, K-frame and chassis. The steering box mounts on the K frame have been known for poor factory welding and cracks, which can allow the steering box to move back and forth. The LCA pivot tubes have also been known to break out of the K, which allows the LCA to wobble around.
Unfortunately, if the rust on your rear frame rails is any indication, you also need to inspect your front frame rails, especially in the area where your upper control arms mount. Dirt likes to collect there and rust is pretty common in that area, which can allow the UCA's to move around in ways they should not.
If everything passes the structural test, a proper alignment for radials is a must. Looks like you have BFG T/A's, which means you should be running alignment numbers like this, NOT the factory published numbers which are for bias plies.
View attachment 1715983514
But let me go back the the structural part. Your rear frame rails
need to be repaired, and possibly your rockers. This is very structural damage that appears to have already been poorly repaired in some areas. It wouldn't take much for the leaf springs mounts or shackle hangers to fail.
View attachment 1715983505
View attachment 1715983504
