Is there a 'cunning' way of mating the MX rack to Cortina uprights?

Are they not too wide giving some nice bump steer? Unless your building something with the same track as an mx5?

Narrowing should not present a problem...access to engineering facilities comes easily

It should just be a case of getting the correct track rod ends that match both the threads on the MX5 rack and the taper on the cortina upright, either that or getting the taper changed on the upright to match the MX5 track rod ends.

Yes,thats why I posed the question,if anyone had done it before and could advise me the parts that would do the job.

what is the thread on the MX5 tie rods?
Pretty sure the tie rod ends i have for my escort rack are standard M16 coarse (correct me if i'm wrong, it happens a lot) as I made extenders for it
Otherwise you could use rod ends if you cann find female ones with the right thread on, then just have some adapter pins turned up with a thread, then taper, then a straight for the ball joint, then another thread on top to attach the rose joint to the steering arm

Ford rack uses M14 thread.

Cortina is probably narrower track than the MX but track has nothing to do with bumpsteer - inner wishbone mounting relationship to rack knuckles does.