Sorry PST, but they're a waste of money. All due respect and all, I think most of your parts offerings are pretty great. But drop spindles are for coil spring type suspensions.
The correct way to do this is to use larger torsion bars. Larger torsion bars mean that the wheel rate (spring rate) is higher, so, there will be less suspension travel. You can then use the torsion bar adjusters to lower the car. That reduces the amount of available suspension travel, which is a problem if you don't install larger torsion bars.
But if this is a pro-touring style build, you ARE installing larger torsion bars. So, you can lower the car with the torsion bar adjusters. How much will depend on the the size of the torsion bars you install. The larger the bars, the more you can lower the car. You will also have to remove the stock lower bump stops, because you'll hit those pretty quickly when lowering. Replace those with a poly button style bump stop, and you're good to go.
The other thing is, the suspension geometry of these cars gets BETTER when you lower with the torsion bar adjusters. The ideal geometry for using modern radial tires is when the UCA is roughly parallel to the ground. At that point, you have the best camber gain curve. You also have less bump steer at that point as well than with the factory settings. Now, that's probably a little short of a full 2" drop. It's close, but it may be a little short. But here's the thing, that's also the point where ground clearance starts to become a real issue, even with the "good" header design (Doug's, TTI's). If you lower the car with 2" drop spindles, and don't actually lower the car a full 2" (remember you still have the torsion bar adjusters) you've actually raised the angle on the control arms. That means a worse camber curve than even the factory settings gave, same with bump steer.
I ran 2" drop spindles on my Challenger for awhile, before I figured some of this stuff out. I took them off, lowered the car just as much with the torsion bar adjusters, and don't have any problems. Like my Duster that is also similarly lowered, I run 1.12" torsion bars in that car.
The only purpose I see to the drop spindles is to lower the car without substantially increasing the wheel rate. Which is fine if you're just lowering for cosmetic purposes. But, if you're lowering the car because you want it to handle better, you're installing larger torsion bars. And if you really want it to handle well, you're installing bars large enough that you can lower the car as much as you can without starting to have other issues. Like running out of ground clearance on the headers, or even running out of suspension travel before the tops of the tires hit the inner fenders at full suspension compression. Which is where I'm at with my Duster. Were I to lower it any more, at full suspension compression my tires would hit the bottoms of the inner fenders. You'd have to raise the shelf on the inner fenders to lower the car more, at least safely.
So, if you're lowering the car for handling, you don't need drop spindles. If you're just lowering the car for looks, then the drop spindles are easy. But it's actually cheaper to buy larger torsion bars and better shocks and do it right.
