RR BMW 4.4 V8 L322 Engine *LOTS OF SMOKE*

Hi guys, vehicle has had a replacement engine fitted due to seizure of the old one, now we have lots and lots of white smoke from the exhaust, with lots of pressure behind the oil cap, so much pressure it seems to have blown the crank seal and its now leaking oil from the bottom, the breather seems a common problem on the 740I BMW's which has the same engine, and just wondered about methods of clearing these effectively, and how to diagnose if its another issue.
regards
josh

i would be asking the fella who put it in to have a look,

the vehicle was bought as spares or repairs, so thats not an option. The PCV valve cleaning/replacement is our first port of call as its a common failure on these BMW v8's.