thrush: you can only do the 24V conversion with the 90-91 cars, afterwards they used a bigger bolt to hold the clipers on so you would have to drill out the hub to accept the M12 bolts
you may have to space out the granny calipers as they use different mouting brackets to the cossie 4wd cars, but the calipers are esaxclty the same

pgt: what sort of fettling are we talking about.................