Thanks all for your useful responses.
I have a spare
oil filter cartridge, so I will remove the current item and re-seat the new one, as i suspect its over-tightened anyway. I had a feeling that I should not have to be tightening it too much.
There is a small amount of
oil pooling on the thread/inner ridge of the
oil filter where it screws on to the remote casting, so I am sure this is at least one source of the leak. It doesn't seem to spray or get worse when idling, so assume this is spreading when under load/speed.
I have a hose connection from one rocker cover to the carb manifold vac, the other rocker cover has a ventilated filler for adding oil, so i guess the ventilation issue should be OK?
Once the car is warmed up it runs around 30 psi oil pressure at tickover, going up to 60-80 psi under acceleration. Is this too much pressure internal pressure? Its a newly rebuilt engine.
On another thread, I realised I plugged the vac advance into the ported vacuum connection on the Holley, so need to swap this to full manifold vacuum, but ignoring poor mpg and temperatures, I don't think this would have an effect on the oil leak?