The drop spindles only move the track as much at the regular 73+ spindles. I honestly don't know what happened with momoparman's car, but the track width change isn't 3/4" per side from early to late spindles.
BUT, they do eliminate any possibility of clearing the outer tie rod end with the rim. Normally, an 18" rim totally clears the outer tie rod end, allowing more backspace to run wider tires. Some 17's also allow enough room to get more than 5.6" of backspace. Not possible with drop spindles, which means you're limited to no more than about 5.6" of backspace, which means nothing wider than a 255 up front for pretty much all A-bodies even with a 17 or 18" rim. Less with a 15" rim.
I've found that the drop spindles are totally unnecessary if you upgrade your torsion bars. The only advantage they give is that they allow you to lower your car 2" without losing suspension travel. But here's the thing, if you run larger torsion bars, you can't even use that travel. Even most 1" torsion bars are almost double the stock torsion bar spring rate. Which means, only about half the amount of travel is needed for the same input force. So, while you can lower the car and keep the same amount of possible suspension travel, you'll never use it. With the 1.12" torsion bar I run (300 lb/in, or nearly 3x the rate of stock), I've yet to hit the bumpstops on my LCA's, even with only about 7/8" of available travel.
I ran Magnumforce drop spindles on my Challenger for a few years. I realized that I didn't need them with the 1.12" bars on it either. I removed them and lowered the car with the torsion bar adjusters to the same exact ride height. No issues whatsoever, despite the loss of available suspension travel.
The drop spindles DO raise your roll center for a given ride height. Meaning, my challenger lowered to the same ride height without drop spindles has a lower roll center than it did at that height with drop spindles. If your car is currently at stock height and you're looking at lowering it, the roll center will change very little, because the angles of the UCA's and LCA's will be roughly the same if the car is only lowered the 2" with the drop spindles and no adjustments are made on the torsion bar adjusters. If you lower the car less than 2", meaning, you install the 2" drop spindles and adjust the torsion bar adjusters so you have less than a 2" change in ride height, you'll have raised your roll center. Probably not so much that most people would notice, but raised it nonetheless.
Personally, I think the drop spindles are a waste of time. Spend that money on a good set of torsion bars and lower the car with the adjusters. One of the biggest advantages of the torsion bar suspension is that it's ride height adjustable.
rayer:
