hi i,ve been doin some research on fitting either a zetec or duratec from a mondeo .
they are desirable engines and they will mate with the sierra gearbox easily
But !!!! to get them to run always seems expensive ie .throttle bodies and stand alone management system always seem to add up to about £2000 .
Try this website for some really good info and they have also found a budget way of getting the zetec to run on salvage parts
hope its of use