I assume that with Scorpio you mean the bug-eye model (as the Granada mk3 was also called Scorpio in the rest of Europe)? The bug-eye Scorpio uses a 7.5" diff, but the rear cover was changed somewhere half way production. The old cover can be fitted to the new diff though. There are also two versions of the flanges for the driveshafts. The 2wd Cosworth uses 108 mm flanges, while all other Sierra and Granada mk3 use 100mm flanges. I think (but I'm not sure) that the bug-eye also uses the 108 mm flanges, like the 2wd Cosworth. But be aware that there is no bug-eye Scorpio that uses an LSD...