I run the fatman spindles. For whatever reason we had to shave part of the caliper to get full clearance. Fatman said it is because all mopars are manufactured with different specs. They work but I would agree not something for the track.
Did you have to shave it on the bottom corner near the allen bolts. The one set my friend had, they had to do that. He had rotor interferance, IIRC. They might not be that bad a piece, but for $500-$600 you'd think you'd be getting something a little more stout. And when you ask them specs on them they act dumb. The problem is are they acting?
But it's all there is. For a project like Fwaugh's were absolute lowering is so important to the build, I'd say you're pretty stuck with them.