I run the 73 Up A body spindles and 11.75" Cordoba rotors with AndyF's Wilwood adaptors and the the Late model Aluminum M/C....works phenominally.

I'd like to know if there is really any weight savings though...the WW calipers are super light but those big rotors seemed about as heavy as the drums and backing plates that were on there. With the oem calipers I'd almost bet it's heavier overall.