as above? will they fit straight on?

i woiuld say... noooooo i think

reason being, cortina calipers are twin opposing piston jobbies, sierra ones are single piston sliding jobs. completely different design

in a word.......no

tom

noooooooooooooooooooo

get in there quick and do a search on ebay for locost under car parts
2 pairs of cortina calipers going for next to nothing then all you need is discs