Torsion Bar Lowering
Thank you for repeating this.
Too many people parrot what they hear when they have no direct experience. A height change of an inch or less, the change in the alignment is so small, it is a waste of money to put it on a rack.
An inch drop/raise is too much change without an alignment IMO.
I've run my car from stock height all the way down to its current height- lowered about 2" from stock. I do my own alignments so it gets checked whenever I make a change to the height or suspension components. If you change the ride height by more than about a 1/2" without re-doing the alignment it will change your numbers enough to warrant a new alignment.
You can look at the charts that Bill Reilly made when he compared the A-body spindles to the later FMJ spindles, he showed all the alignment changes based on dive and rise. If you're lowering the car you can just look at the dive numbers for the amount you want to lower and see clearly how much the alignment has changed. For example, a 1/2" of dive on the car used in the article almost doubled the caster for both the A and FMJ spindles (adding almost 1°). And the caster went negative by .14° or .26° depending on the spindle (although that's a good thing unless you're still running bias ply's, 0 camber and radials is not the best choice). Negative camber gain is better with the FMJ's. Toe changes are also more significant with the FMJ spindles, making the need for a new alignment at the 1/2" mark more significant. You can see all the numbers yourself here
Swapping Disc-Brake Spindles - Mopar Muscle Magazine
Bottom line is, if you care about how your car handles and you lower (or raise) it a 1/2" or more, you should get an alignment. No, it won't peel the tread off of your tires, but a 1° change in caster changes handling. So can a 1/4° change in camber, and so can a 1/32" change in toe. And that's just at a 1/2" drop. Granted if you have stock alignment specs the changes from a 1/2" drop are an improvement. But if your alignment is already set where it should be it's a big enough change to want it corrected.
You should also upgrade your torsion bars to lower any amount from stock. The stock torsion bars are too soft even at stock height, you use the bump stops quite a bit. Lower the car a 1/2" and you'll be using those bump stops a lot more, which hurts ride quality. If you lower the car and want the suspension to function normally, the torsion bar diameter needs to be increased. For the 2" drop I run I use 1.12" bars.