Yeah, I am planning to put WB statesman rear discs on mine at some stage.. I'll pull the shitty 6cyl diff out and put a V8 one in at the same time...

The statesman diffs are wider, but it is easier to get a V8 salisbury (from a ute/van) then get the statesman axles, calipers etc and fit them...

The caliper has to be rotated a bit, otherwise it will foul on the leaf springs.. :( Then you will have to fit the statesman handbrake cables...

You will also need to fit the statesman master cylinder aswell...

Hope that helps..

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Damn it!!! HK beat me to it.. Lol