518 in an A body

If you're thinking about driveline angles, I don't think it will be an issue.... because
On my 108wb Barracuda, I am hanging a GVod off the long tail extension, and that makes my driveshaft around 3ft long. And my car is lowered an easy 2 to 3 inches. And I have been able to minimize the angle related vibration and oscillation to just barely perceptible. And most of the time, the CenterForce flyweights are covering it anyway, lol.

Another thing about the dropped K , that I was thinking about is that; as the K goes down, the body goes up... taking the UCA up with it. And when that happens the camber changes, pulling the top of the wheel inwards. And after a re-alignment,that might work fine in a straightline with a frozen shock. But what happens in a bumpy turn; IDK.
Well I sorta do; have you ever watched the steering of a Mopar as it's leaving the starting line. As the front goes up, it steers one way, and when it crashes down, it steers another. It's all over the place and IDK how the driver keeps it straight, if it bobbles from the line. Now imagine that in a bumpy turn.
I mean IDK, just asking.
If you manufacture your own K-spacers, you can put a centering ring on the frame side, and duplicate the centering device on the bolt-head side.