your right b310gx, i went to the wreckers and any tailshaft yoke off an aussie 180b/200b will fit sweet. i also got my tailshaft done some time ago to 180b size renewable unis (highly recomended.) so it'll be a hammer off hammer on job for me. I'm going later today to source a slave cylinder so i'll post part numbers for that one too.
One point of interest though, looking at the speedo cable drive on the box, the standard 1200 cable still screws on and operates fine, but the little plastic driven gears inside the box have a different # of teeth,17 for 60a and 19 for 63a i think. I put both boxes in forth,(1:1) and in one full rotation both boxes have five and 1/2 driving teeth pass the same point. I think this means that your speedo will read less than your actually doing, as the gear with more teeth will spin slower. Have to wait till it's on the dyno to find out for sure.