Are the rear 4x4 Cosworth joints the same as a standard Sierra?

I have found a guy local to me who can get the joints and he says they are 100mm, same as mine BUT they are listed none-cosworth?

I thought the only difference was 2wd M10 108mm (i think) and 4wd M8 100mm

The joint doent have no abs ring on it or anything special

Please help!