I found part of a discussion on this topic on ozdat, but nothing more.
Here's a pic stolen from there.
I most curious about wms differences between them, though i realize it could alter brake rotor location as well. Let's ignore that for now.
WMS= left side of yellow to right side of red.
According to the info on Ozdat:
S12 hubs- ylw=96.5mm, rd and blu=21mm, rear hub=55.5mm.
910 hubs- Are same as S12 above.
240K hubs- ylw=99mm, rd and blu=34mm, rear of hub=34mm.
Z31 (5stud) hubs- ylw=?, rd and blu=17.5mm, rear hub=57mm.
DR30 hubs- ylw=?, rd and blue=17.5mm, rear hub=?.
So adding "rear of hub" and "red and blue" we get:
S12: 76.5 mm
240K: 68 mm
Z31: 74.5 mm (5 lug)
Can any of you guys measure any other hubs you have laying around and post the measurements?
I'm hoping to measure my S12 5 lug hubs tomorrow and post that up.