9" drum brakes on a 8-3/4

Thank you, but as I understand, the 8-1/4 has the same 5-bolt backing plate as the 8-3/4. And there were Mopars with 8-1/4 and 9" rear drums out there.

The other thing is that my Dart was very fine with its 9" drums. Even at the German Autobahn and more than 55 mph :D It had a strong running 318 in and stopped very well.

New situation is that it will never be street driven again. So we don't have to worry about passengers lifes.