Pardon me butting in, but my feeling to some extent, if your considering a Mondeo depends on the month/year of manufacture, or to put it another way whether it has a silvertop or a blacktop engine originally. It just makes it a lot easier to stick with the same engine mounts, auxiliaries, etc.

I'm not sure why pa sjo says the earlier (silvertop ?) engine is stronger. Admittedly the main caps are a bit smaller, but generally the block on the later engine is far more rigid, complemented by the alloy lower crankcase. I know of reliable blacktop engines running in the high 200hp and other more exotic ones over 400hp.

As long as you change pistons/rods as complete sets, as the crankcase is the same height, you can use what seems best. Silvertop (as Performance Ford did, but didn't write up - yet) Blacktop, American(ST170) or Focus RS.

Its the head/cam/valves where the major differences are found. Only oversized valves for the silvertop are available in Europe, its USA for a blacktop. I actually use silvertop valves in my blacktop head, but shimming costs are prohibitive. Cams for both silvertop and blacktop engines aren't a problem.

Of course you can take the cheating route.....I found a solid Mondeo 1.8LX July 98 as a winter hack. Unfortunately the cat failed and blocked the exhaust. So I cured it by dropping a Focus RS engine in...seemed to stay with a Focus ST3 (285bhp) reasonably well.