Need new suspension

The best suspension geometry- roll center, camber curve, bump steer etc occur when the control arms are roughly parallel with the ground. That phenomenon happens when A-body's are lowered pretty significantly, basically where my car sits right now. But it's not quite a full 2" drop.

A 2" drop spindle lowers the car 2" while maintaining the stock control arm angles. That means that the camber curves stay about the same as the stock geometry. The roll center changes because the car itself is lowered, but it still isn't as good as what you get from lowering the car with the torsion bar adjusters. It stays the same relative to the car, and is lowered only because the car is. But most of that stuff is pretty minor. You basically keep the stock suspension geometry, but lower the car 2". The nice part is that you keep the same amount of suspension travel, so, you don't have to change the torsion bars. It basically lets you run any torsion bar you want and still drop the car 2" without worry about bottoming the suspension all the time, instead of having to go with some really big torsion bars like I've got to get that much drop.

The "problem" is that most folks don't drop their car a full 2". For example, you install 2" drop spindles, and then set the car up with a 1.5" drop compared to stock. Still a pretty significant drop compared to stock. But as far as your suspension geometry is concerned, you've actually raised your car a 1/2". Which will have actually made your suspension geometry even worse than stock. You had to compensate for the 2" spindle drop by using the adjusters to raise the car above where the stock ride height would have been.

So, that's my beef with drop spindles. The stock suspension will allow for more drop than most people usually want. If you match your drop in ride height with the appropriate sized torsion bar, you end up with better suspension geometry and better handling all the way around, and you don't have to drop $500 on spindles. Most folks that want to lower their cars also want them to handle better, so buying new torsion bars is something they would do regardless. Which means you have $500 you didn't spend on drop spindles to spend on something else.

The drop on your car though is at least 2" from stock. Which means as long as you keep your current ride height, you won't have the issues that come from running 2" drop spindles with a less than 2" drop in ride height. My only concern is that other issues come up, like the tires bottoming out on the inner fenders because the car is 2" lower but the available suspension travel is the same as a stock car.

As far as the drop spindles go, I would use PST or Magnumforce. I ran the Magnumforce drop spindles on my Challenger before I improved my knowledge of torsion bar suspensions. I probably put 30k miles on them without any issues. That was before PST sold them. Fatman also sells a set of drop spindles, but they're fabricated. I'm not a fan of welds in my spindles. I pulled the drop spindles on my Challenger when I redid some other suspension parts, and found I could lower the car to the ride height I wanted without them (and then some). So I pulled them and sold them. The Challenger handles better without them. Small caveat though, E-body's have a little more available suspension travel based on my experience with my Challenger compared to my Duster. The E-body's can be dropped with the stock suspension and larger bars until you can't even drive over speed bumps without leaving the exhaust behind. I've actually raised my Challenger up a bit from it's lowest, I got tired of dragging the headers everywhere I went. And those are above the steering link headers.

And of course I would go with the larger torsion bars regardless. The K frame doesn't matter, I assume you're using conversion mounts then?