The difference between a ditch and the center of a traffic lane is maybe a tooth on a spline shaft. If much more than that is needed, likely someone replaced a rag joint. That "on-center" position is like a narrow range at the center of travel. I dare say none of these trucks drive with the precision of R&P steering, and while that steering wheel may not move far, it never stops moving even to go straight out a long west Texas road.

In reguards to trac bar or centering an axle someone mentioned. I once noticed that my right front tire was further out than the left, measured a 3/4" difference. I had not paid it attention in over 20 years, but once noted, it became hard to not see. I know, "silly" huh? I made a 3/8" thick spacer plate, drilled two holes, placed it between the left frame rail and the trac bar bracket. Used longer grade 8 bolts. It's about perfectly centered since. As a side benefit, it centered my steering wheel without any clocking, though it had pointed slightly to the right for years.

As to C-bushings, I put the first step red ones in in the '80s, maybe was 2 degrees, was suggested for stock to 4" lift, with the '78/'79 linkage kit, was like a new truck. Red Head was the next step up. Eventually, a new drag link and more red trac bar bushings due to wear. Still can't detect wear in tie rod ends as they only move when steered L-R ... unlike the OEM '77 setup did.

 

Mine is '79. Thanks for the info regarding length of track bar I was under the impression they had to parallel and the same length. Good to know there's some wiggle room.

I have 3-4" lift springs for the front (as they're labeled). When I replaced springs front and rear a couple years ago, I went with heavier rate leaves meant for the F250 and gained about an inch in height out back. The replacement coils up front were supposed to be big bronco replacements and I was hoping would bring it closer to level since they were supposed to have a heavier rate than factory. I did gain about 3/4" initially but they have sagged since then and I have a decent rake now. That would be fine if I planned to tow/haul with it, but I don't. I have my diesel for that.

Anyway, looked around for coil springs, found some heavier rate springs and if I did my math right comparing spring rates and measuring how much the current coils squatted when the full weight of the truck was back on them, I'm estimating the 3-4" "lift" coils should give me a net lift of 2.5 to 3 inches once installed. If that makes the nose sit higher then rear I'll compensate by lifting the back with add-a-leaf or a different block.

I'm using 2 degree poly bushings currently and will swap those as needed and will make adjustments to track bar bracket and pitman arm as needed too. I need to get the new springs in and the engine back in so I can see what it needs for adjustments there.

Yes, I was surprised the axle was shifted to driver's side. My previous '79 and my buddies '75 that were lifted the front axle was shifted in the opposite direction. I'm sure every single F100/150 4x4 that rolled off the assembly line with this suspension set up the axle was shifted one direction or the other. Maybe 2 might have tracked true... until the springs started sagging anyway.

 

Parallel and same length is best, but if not exact, whether you notice or are bothered by bump steer depends on how far from "parallel and same" yours are and your roads traveled, etc. Lots of variables.

The little '82 Plymouth police cars (mine weighed 4,200 on scales loaded up) we got, the tie rod assembly had three sections. The center link left end attached to the pit-man arm, but the idler arm at the right end was angled different and so the center link was not parallel to the ground, which meant one tie rod was angled different than the other, so there was some bump steer. The control arms, etc were fine. I knew guys scared of those cars, because like if you crossed the Maury River Bridge expansion joint SB at triple digits it might near wanted to change lanes. One got used to it quick, and it was hardly noticeable at normal speeds. Fix was to remove the idler arm, move a hole (welded thick washer to frame, redrill hole through washer) and reinstall it, and it corrected the angle of the Idler arm upwards. I had to relearn stepping onto the Maury River Bridge when after one then, took a couple trips.