Looking at a '68 B-body, rebuilt suspension. restored 75,000-mile car...
For setting ride height, there's the bolt, the swivel that's captive & the control arm, and the blade the bolt adjusts for ride height.
Car sits even R/L, drives fine except a consistent light pull to the left. (new radials, road crown cambered slightly to right, tire pressures @ 32)
Rt adjusting bolt has about 1/2" thread showing below swivel, but Lt bolt is tight against its swivel.
Is it possible that the arm or blade was mis-clocked during reassembly?
IIRC, it's a hex, so I'd expect that wouldn't translate to the discrepancy; I'd expect more (being 60 degrees per hex face), right?
Never had one with that difference (usually 1/2 inch to an inch exposed thread).
I've never had a weak or failed torsion bar even at over 2X that mileage, and nothing besides that adjustment indicates that's the problem.
But I guess anything's possible, (thinking about it as I type).

In my limited experience, if the bar was off by one position, either way, it would be very obvious. Either the front end would be bottoming out, or it would be way high in the air. My guess is that the bar on that side is weaker. Just my $.02

mis-matched bars
LH bar twisted/failing?
"fixed" anchor points on crossmember

Take as good of look as you can at the lower control arm bushings. If really wiped out, can show adjustment like that.

The bar should have nothing to do with the pull..the height is the same than it's a weaker torsion bar...double check that wheel alignment

A little further down the rabbit hole...
Looked at the T-bars, ends are stamped 456R/092 (R) and 457L/231 (L).
They measure .850" about midway.
Everything looks basically new or rebuilt.
Restoration has about 4,000 miles on it, car had under 69K on odometer before that.
Those 456/457 #s don't show up on the broadcast sheet ("779 left" / "778 right"), nor in my MP chassis book.
I suppose it could have drag race bars in it (FSM spec is .88"): though that doesn't match the rest of the restoration, the car did make a few passes in its past and has Calvert shocks in it.
(Possibly misleading comparison/reference: my SB Duster has even smaller bars, been in there almost 50 years, no sagging, but it's 3000 lbs & has never seen street use.)

I'd like to sort this out before the wheel alignment, will also try R/L tire swap to check for "radial pull".

a body torsion bars are shorter than B body, so wheel rates are different if the same diameter.
do a google image search for torsion bars, there are charts that will show wheel rates. I would just replace the bars. .850" is too small IMO.


edit: oh here you go. the moparts archives...

http://www.moparts.org/Tech/Archive/susp/16.html

That's the same chart that's in my MP Chassis book.
Yeah, .850 is small, stock spec for this application is .880 (FSM) or .900 (FBBO & other sources).
It doesn't act as "lively" (lifting the nose) as a drag car when driving, and seems quite firm when you bounce-test it.
Would have never guessed they weren't stock had I not measured them.
But if they aren't up to the task of 4,000 miles of street use, that could maybe explain the LF adjustment being used up.
And the 456/457 #s don't correlate to anything I've seen so far (the chart or the broadcast sheet).
I don't have an original parts book to check.
Guess it's a new pair of .920 bars for the thing, to match the XHD rear springs...

The pull is not from the bars. Imagine if you had a thick bar in 1 side, thin on the other. Adjusted the ride height so it was the same. If the car is just cruising down the highway at that moment the difference in left to right has no effect but the car pulls to one side.

That is coming from the tires or the alignment. Swap tires left to right and report back. I'd also scrap the road crown alignment and match left to right caster and camber as best as you can.

As for the bounce test and thin bars. Most likely the shocks are preventing and bouncing you are expecting because .850 is a pretty thin bar.