Several years ago a friend tried to fit the whole bug eye Scorpio ABS system to his 2wd (regular) Sierra, but he said the front ABS rings were a different size on the bug eye Scorpio than on the Sierra. I expect the front ABS rings to be the same size on all Sierras (regular 2wd, Cosworth 2wd, 4x4) and Granada mk3 as well. But I never checked this myself.

The 'basic' MK60 system was used on the later E46. An evolution of that, the MK60e1 is used on the 4 cylinder E9x. IMO the MK60e1 is easier to use than the MK60, as the e1 has the inlet pressure sensor integrated in the module (hence the 'e1' name). On the basic MK60 you need to hook up 2 pressure sensors to the inlet yourself, one for the front supply and the other for the rear supply, so that includes additional wiring and brake lines.
However, the MK60e5 system is again an upgrade over the e1 system. The e5 system uses 5 internal pressure sensors (hence the name e5), one on the inlet and than one on each brake line to the wheels. It is said that due to those additional pressure sensors the e5 ABS system can modulate the brake pressure even better than the other 2 systems. The downside of the e5 system is that it uses magnetic rings instead of toothed rings. However, people have sort of 'cracked' the coding and can now change the type of ring on the rear axle from magnetic to toothed rings. On the front this is not possible (yet).

So because of the additional performance I would really like to use the MK60e5 system, which is the ABS/DSC system used on the E9x 6 cylinder cars. I plan to use the rings with 48 teeth on the rear and some magnetic rings on the front. The magnetic rings have 96 pins, so the signal should be equal to 48 teeth on the rear. I have ordered the AIC 55465 magnetic rings, which have a diameter of 71.5 mm. It will be a very tight fit within the front knuckle, as I measured that to be 71.7 - 71.8 mm. Hopefully there is also some coating on the rings that could rub off slightly if needed. If it really doesn't fit I guess I will also have to have some 48 teeth rings made up, as I cannot find any magnetic rings smaller than the one I ordered. The other option would be to machine the knuckle for a slight bit more clearance, but I really don't want to do that.