Im sure the fiesta is the same as the escort if thats the case then if you want 4+4 calipers you need 2wd disc's. If you want to use 2wd 4 pots then 4mm needs to be taken off the mating edge of the caliper, where it bolts onto the hub. The 4+4 way is easyer but the 2wd is ment to be better. Have a look here

https://passionford.com/forum/viewtopic.php?t=248404

or on here

http://www.rsbible.co.uk/