The mondeo four cylinder engine (Zetec) is a very usable engine, you will need to sort out the fuelling and ignition, the standard system can be adapted but it's probably easier to use the megajolt/megasquirt electronic unit
The engine will also run on carburettors, usually twin 40 DCOE webbers.
This is a good site about the engine too
You'll need a rear wheel drive gearbox, either the type nine as used in the book or the MT 75, plans are on the forum for the fitment of this box. These gearboxes were fitted to the Capri, Cortina, Sierra, Granada (type nine) and later RWD Fords, Sierras, Granadas, Transits (MT75).
The Mondeo front upright is not really suitable for our uses, being optimised for front wheel drive, The rear upright is completely unsuitable as there is no facility to fit driveshafts for RWD.
In short you could use the engine but the rest of the running gear would need to be sourced from a Sierra, the other alternative would be to find one of the rare 4 wheel drive Mondeos and only fit the RWD axle.
Hope this Helps