[Coupeguy2001]

Those rotors look like GM G body rotors.
I would start with Speedway motors.com. They have 5 or 6 catalogs, early iron, classic, truck, racing, etc. I would go to the racing catalog, and look for a 1/8" spacer to push the rotor out if the spindles are long enough. Then I would see if the 78-87 seals fit those rotors.
If those spindles are a brand, call the manufacturer's hot line, and tell them what you are facing.
They could tell you what the spindle -rotor matchup would be.
All of those designers look for parts thatyou can buy locally at a parts house, and design the spindles, tie rods, etc. to facilitate them making kits as cheaply as possible while maintaining strength.