used 9c1 springs- thoughts?

I'm going junkyarding this weekend and was wondering if it would be worth my time to get a used set of rear 9c1 springs for my caddy? I know of one ('93) in the yard that had 135-140k on it (all the others have unknown mileage as the clusters are gone)
the car was a detectives car while in police use and the interior was in pretty good shape.
I'm just wondering, what is the service life of these springs (given they are "heavy duty") and would it provide much of a handling difference in my fleetwood? my car has stock rear springs and shocks and the rear springs. my shocks have long since blown out (those are getting replaced too), and the springs are toast- most likely due to the blown shocks (the back end sags about 2 inches with no weight and sags about 6 inches with 150 lbs of junk in it)

The springs should be good, especially if they are HD. For the price of used springs, you have nothing to lose. Just be careful removing the front ones. It is often easier to unbolt the lower bushings and drop the arm from the inside (remove the shock first).

I don't plan on taking the front springs (mine are still good) but if the price is right, I may take them all. My mechanic said that front springs are dangerous to remove (something aboout they can pop out.)
Also, is the 9c1 front sway bar an improvement over whatever front bar is stock in my caddy? I need to do something about stiiffening up the front (all the parts that wear out in the steering rack have already been replaced)

When I get my car back from my mechanics, I plan on overhauling the suspension (severe service shocks, rear springs, 90 tow pkg 350 brougham sway bar (same as 9c1 bar IIRC.) It handles like a 18.5 foot marshmellow and I hate it. (And no I don't care that I'd take away the float...thats what the lesabres for)

A lot of people try to make changing front springs more dangerous than it is. If you follow good practices, you will not get hurt. Use some kind of restraining device on the springs, so that they can not escape. A chain or heavy nylon rope tying it to the frame is a good start. Using a spring compressor is suggested, but not necessary if you lower the whole arm. Put the car on jack stands, remove the shock, and put a floor jack under the arm at the spring pocket. Unbolt, and separate the lower ball joint, and then the bushings. lower the jack smoothly, and not too fast. You may have to persuade the bushings to come out of their mounts. Reinstalling is the reverse. As long as you control the springs, you won't get hurt. At the junk yard, Removing the bushing bolts first may be safer, because the spring will tend to go toward the engine, and you can workwith a long pry bar from the outside when removing the bolts.

Junkyards here don't allow jacks of any kind. Is there anything I can use instead of the jack to lower the control arm?

No jacks,how in the world do you get anything done besides overpaying their help?Makes no sense at all not to allow any jacks!The way Fred said to remove them is the safest by far but
a jack would still make everyhing better!

On the junk yard car, take a long screw driver, and work from the knuckle side. If the yard has an A frame, you could lift the car and put one of their stands under each arm. Then when you have removed the shocks, the bushing bolts, and the lower BJ loose, you can lift the car to allow the suspension arm to come out. You may have to pry the bushing ends of the A arm to get them out, which is the reason for the long screwdriver, so you do not have to get under the car. You can do both sides at the same time, if you lift at the center of the car.

According to the people who run the yard "you don't need a jack because the cars are on lifts" (wheels are about 2 or 2.5 ft off the ground (cars are on welded frames made by welding rims and metal piping together, which makes it easy to get under the car)

You don't pay for help from the yard workers though (and the parts are fairly cheap). I'm not sure if they'd help me pull springs though.

Can't bring jacks into my local JY either. My suggestion: Find a frame jack from a box Caprice and use it under the control arm.

Did you check on whether they have A frames? You can lift the cars with them, to remove some larger parts or repositiion the stands to remove parts under the stands. All of the yards here have them for removing engines. You can also use them to lift the entire end of the car. They are not going to help you, so use your head and make it easy on yourself. I have given you the best help that I can, and my way is usually tried and true for the least amount of effort on your part. You can speculate a worst case scenerio if you want, but until you are there, you will not know what you have to work with. You can try taking them off any way you want, my way is easy and safe.

One more question...would there be a big difference in handling from changing my stock FWB (non tow package, non d'elegance) front sway bar to a 9c1 front sway bar (Once I change the front shocks to severe service shocks)?
I also recall something about guys changing the front sway bar bushings and firming up the front end. Does this ring a bell for anyone?

It will roll less in a corner, and it will tend to put more pressure on the spring opposite the bump/dip. This would make the suspension feel a little stiffer, because both wheels will try to deflect, and the individual wheels will not move as independently.

I am finally going to tackle installing the rear springs (ended up getting ones from a 110k mile fire chiefs car last summer). I cut out the shocks and used a prybar and a big screwdriver to walk the springs out of what they sit on since the rear axle would not drop down enough for them to drop out.
So for my own car
How do I lower the rear axle enough to take out the rear springs? (I'm guessing I have to unbolt a pair of the control arms?)
Should I tie the springs to the frame to keep them from bouncing out and damaging something?)
once I set the springs in place, how do I raise the axle back up into place? floor jack?

Put the rear of the car up on stands.

Unbolt left side lower control arm axle side. Put your floor jack under the right side tire. Jack up until the spring falls out of the left side.

Replace spring, put back control arm. Repeat for opposite side.

Done.

Kevin,listen closely because I have done it this way years ago and recently saw the method again on Hor Rod.Go buy about a 4 foot length of 1/2" threaded rod plus 4 thick 3" diameter washer,Remove the shock and install the threaded rod in place of the shock.Mount 2 of the washers on the bottom of the rod about 2 inches up and then thread on 2 of the nuts.At the top where about a foot of rod is exposed put the other 2 thick washers on top of the shock opening and then the nut goes on.Tighten the nut until its snug against the washer.Knock the lower ball joint loose or if you prefer the inner mounting points instead.Once everything is loose start loosening the top nut thats now holding the spring tension.Its a lot of work but its safe and with a GearWrench on top its a lot less work.Just slowly loosen the nut as the spring decompresses and you dont need a jack.