For a 2 litre 4 cylinder engine I think it's still very good. Some Mitsubishi engines might be as good but I don't think any 4 cylinder engines from the same era are better. And it's a bit pointless to take larger 6 cylinder engines in the conversation... Because then again, big block V8's are better than 6 cylinder and so on.

And we have to remember, Cossie was rally car originally so 6 or 8 cylinder engines would have been worse taking into account the weight distribution, and they weren't even legal in Grp. A use. If you compare Sierra Cosworth to XR8 (with 302 V8) or even a V6 Sierra you will probably find the two latter more nose heavy and worse handling.

There's loads and loads of Cossies running 300-400 bhp, how many Delta Integrales, GT-Four Celicas and other direct rivals you see running that kind of horsepower?