That kit is specifically for a magnumforce 2” drop spindle. Are you running them?
I’ve run the magnumforce drop spindles myself in the past for a bit with stock Mopar disks, so, I know they use all the same wheel bearings and stuff as the stock 73+ disks. And I know the stock caliper brackets work with those spindles. But, there are differences between the margnumforce spindle and the factory ones (obviously). It could be that the caliper bracket position is slightly different, which may be causing the issue.
Have you called wilwood? Or magnumforce? Somebody must know why that kit is specific to those spindles.