There may be an alternative rotor "hat" that mounts on the same bearings on the stub axle but has the wheel mounting face out further (like a designed in spacer).
I know that early holden front ends for example, as sometimes used in hot rods, HK-HG can carry Leyland P76 rotors to reduce the track bringing the tyres in under the rods guards. This also gives them a Ford bolt-pattern to match the 9" rear.
Try asking someone like Rod Hadfield at the Castlemaine Rod Shop (
www.rodshop.com.au ) who has been doing this sort of stuff for years.