Are the flanges that connect to the prop shaft different? I suspect they are but wanted to check as i know someone selling one for a westie?

Thanks

Depends on the year of the axle --- the flanges on Escort axles changed in 76 when the Mk2 was introduced and a bigger flange was fitted to bring it in line with the Cortina Mk3-5 this applied to both types of axle and all the different propshaft joint types that were used on the MK2 Escort.

Just to finish what BritishTrident started, the "big" flange axle flange does indeed match the Sierra flange (I've just fitted my Type 9 to Capri 2.8 axle propshaft to my Sierra diff)