Although they are both MT75 boxes, that is where the similarities end. The gear level on the Transit box is a lot further forward for a start. They are a no-go really.

If you want an MT75 box, get hold of "Stixy" on the Ford Sierra Owners Club forum as he will undoubtedly have a couple around as he has got over a dozen Sierra models in his garden, with about another 50 cars worth of parts.