My 72 Dart is still Squealing after alignment, It done fine before on mountain curves, put New leaf springs on, drove it & on some mountain curves it has light squealing, but on flat curves it don't, So I go to have a alignment & front raised up a little, seem like it went straight, rides a little smother, but drove it back up on the mountain & its still squealing around some curves,.. & I drove it just the same as I all way have before I put leaf springs on!.. The springs are in the holes, Could I over tighten the u bolts on one side & it do that?... He set the setting for everyday driving!.. Any suggestions?...

Maybe the new springs have changed the slop in the suspension and you are pushing too hard on the new more solid set up. I also would think for a cornering car you would want the front lower not higher. Over tightening the Ubolts won't effect the handling. You want them tight enough that the rear end won't move on the perches.

If you're sure it's in the leaf spring area, it would be a pain, but you could pull the bolts out and smear some more grease up in the eye holes.

I had a squeaking issue after replacing the hangers and rear springs.
Drove me crazy until I took it all apart and found interference between the 2.
Once a ground a little on the hanger it solved the problem.

Are you talking about tires squealing or suspension squeaking? If it is tires squealing then Does it handle any different when it makes this noise? Does the front or rear of the car push you out? If you changed the spring rate significantly it can and will affect the handling. It's a balancing act between the front and rear.

You're going too fast in the turns.

Does it have a Sure-Grip or even a spool? If so, tire squeal is very normal on hard & / or fast turns.

I saw on hear in tech archive you can't go by factory specs, don't anybody have anything to say on that???... So you can't go by the old repair books?
So the rear can't be off as long as its in the hole's?

I assume you mean tire scrub squealing? I was working on a clone Six pack Super Bee yesterday and installing the Dana from a complete rebuild. I dropped the springs out to paint them and noticed the right side spring perch had two thin shims in it. I assume someone had a four wheel alignment. It is a well done car. Maybe check the alignment on all four corners

There is no rear alignment on that vehicle. If the rear is off the geometric centerline and thrust angle will be off. Alignment machine will show this. If it is off, the rear spring perch is broken, or loose. If the car has radial tires I set camber as close to zero degrees +/- 1/2 degree....try to get as much positive caster as possible. Usually hard to do if still has factory front suspension. FirmFeel.com has great parts. Toe-in 0 -1/32" in total.

You can actually alter the rear alignment by using the shims mentioned in one of the above posts. Adding shims between the front spring hanger and the mounting boss on the car will effectively push the rear wheel on that same side towards the back of the car thus altering the relative position of both rear wheels to the front wheels slightly.

the build quality back in those days was horrible. the rear could be in there located anywhere, with up to 1/2" variation from factory blueprints without having broken, or worn out parts.
very easy, but labor intensive, to relocate closer to specs by shims and slotting holes where needed.
measure closely [twice or more] before cutting [hole slotting, shimming] once.

Are you pushing the car faster now than before the work?
If so your now making the tire work harder to go around the corners and it is talking to you maybe saying your on the edge, dude
If your not going faster around the corners now something is not right with that work
Let us know what you find out and do to take care of it

I'm kind of with Cab on this, if everything is correct (big IF) are you going faster through those curves now?

What are your alignment specs? Everyday driving specs don't mean much to me. I'd like to see the angles and degrees. There are many, Many, MANY alignment places where an alignment consists of setting toe and nothing else. If this is the case with the shop you used, there are several ways your alignment could STILL be off, possibly by a lot, despite the fact you paid for and they claim it was aligned.

Well I been driving it & its steal doing it on 3 sharp curves, Its a short tire squeal or you could say a tire chirp, I took it back to wear I had alignment & he sead it seems fine & it just my tires, but if it my tires why did it not do it before, I know better then that, So I've been just driving it, its not as loud now, with music on you don't hear it. Something I am wondering about is can you over tighten leaf springs u bolts because they do look it to me???

Rare, but I will quote myself;

More pics

By the looks of that spring pack, I would suspect you may have one or more broken leafs. Even if the leafs are not broken, the ends of each spring could be dragging on the longer leaf above it, that could give you a squeak as the suspension moves up and down. If you jack the car up, and look at the ends of each spring leaf, you may be able to see scraping or wear marks on the longer leaf. Gene

So new springs can be broken??? I hope not, lot of work putting them on!

Post a copy of the alignment sheet. That will show where this car is set at.