My response from Wilwood:
Hello Kyle,
Thank you for the inquiry with Wilwood Disc Brakes.
Our EPB calipers are a fairly new product and at this time we only have kits available for new style 9” ford rear ends.
https://www.wilwood.com/PDF/Flyers/fl485.pdf
https://www.wilwood.com/PDF/DataSheets/ds1353.pdf
Regards,
Wilwood Disc Brakes