So, finished putting it all back together, and unfortunately all is still not well.
Left it idling on the drive until operating temp was reached and all appeared well, no smoke, sounded ok,(well, as good as a fully de-cated, straight through system sounds), good oil pressure, left for an hour or so, started back up and taken up to temp again, and all ok as before, so decided to go for a short drive to test things out and oh f***, as soon as revs go above 3500, clouds of smoke and misfiring again, needless to say turned round and came home sharpish, amid lots of smoke, and lo and behold oil coming out of the air filter again
So to my mind there are still pressurisation issues, causing oil to be pushed out of the breather into the induction system hence the clouds of smoke and miss fire due to oil soaked maf, but what? Internet search suggests PCV valve could be the prob, but cant find any ref to one on this engine, any body got any ideas? beginning to lose heart at the moment