Obvious upgrade is a 2.0 Zetec. The St170 badged as a Duratec will fit and is better still. You will need to tip thousands into one of these to get over a real 200bhp.

None of the proper Duratecs will fit your box. If your box is the lower duty box as found in the mk1 1.8 Mondingo then it’s a non starter any way as it won’t hack it.

The mk1 also come with the 2.5 v6 Duratec 25 with the mtx75. If you could get the box and shafts from one of these and fit the 3.0 St220 Duratec 30 engine. This would do the 300bhp with head work, cams, throttle bodies, the whole nine yards.

Now that would be a screamer