There’s a new 11 litre engine coming from DAF at Euro 6
truckingtopics.co.uk/dafmx-11euro6.html
They reckon a smaller engine working harder is the way for many applications to go at Euro 6.
It’s up to 440 hp.
They had to do a new engine as the old pr engine could never meet euro 6
The logic seems to be put the engine under loads of stress ( at the two ‘haulage ratings’ ) to get exhaust temperatures up. 
Which doesn’t seem consistent with the fact that the thing also seems to work fine at the lower distribution ratings. 
Bearing in mind modern day 90 kmh limiter settings it would probably be more logical to just settle for the 370 hp spec and just lower the gearing for use in ‘haulage spec’ to help it to get up the hills. 
But the comment,that ‘ultimately the engine may not be as durable as it’s larger stable mate’,seems no surprise to me at least at those 400-440 hp output specs.
So its just like the last “daf” engine,a Leyland with a bigger oil pump and crank journals. Whoopee dooo.
Didn’t know Leyland ever built one with dohc.
I do remember one without a cylinder head though (wakes up screaming!)