"Stupid question- What's the difference between using drop spindles and just adjusting the torsion bars to lower a car with stock spindles to the desired ride height?"
The problem that I see is that in some cases, additional suspension travel could mean that vital underbody parts will now get closer to the pavement as the suspension compresses.
Not good.
Imagine even with a stock oil pan...when you are running down a poorly maintained road, suspension going up and down. If you hit the brakes JUST as the suspension compresses, the K member hits the ground, the exhaust, the tires hit the fenders, etc.
