Hmm.
So looking at the construction, would it be difficult to modify the spindle so that it had a 1" drop? Or, alter the overall height (make the knuckle itself taller?)?
And, what's the ballpark production cost on a set of these?
I've run 2" drop spindles before (from Magnumforce). The issue that I had was that the bump steer is increased compared to a car with the factory spindles lowered to the same height. And, actually running the car 2" lower is fairly close to the limit on an A-body because of other components (the inner fenders, the header flanges, etc). I came to the conclusion that for a car set up for handling you're better off using the factory spindles with the large torsion bars you'd be using for a handling car anyway, and the resulting suspension geometry is better than both factory and what you get using a 2" drop spindle.
But, a 1" drop with the spindle, coupled with ~1" of drop using the torsion bar adjusters, and possible a slightly taller spindle would likely produce better suspension geometry. And it would be easier to maintain the overall amount of suspension travel - I've kept my travel about the same, but I use tubular LCA's, 1.12" torsion bars and a very short lower bump stop.
A 2" drop spindle is kind of the aftermarket industry standard, but it really doesn't match up with these cars very well. A 1" drop would be better for most folks, whether it be people just looking to lower the car a little bit but retain most of the factory suspension parts or full on AutoX/road race cars looking to be lowered to the maximum while retaining geometry and suspension travel. Someone would have to run the numbers, but something like a 1" drop with a 1/2" taller spindle overall would likely improve suspension geometry for those that care about that kind of thing while also lowering the car enough for folks that care about appearances but also don't want to leave their headers behind on the closest speed bump.