After a lengthy read on this site I think I need to attach a small inlet filter to the small tube on the back of the left rocker cover:

Connect a PCV valve to the flametrap on the front of the right rocker cover and run that to the full manifold vacuum on the carb (a Holley 4160 390cfm) :

My concern is that the diagram above shows a PCV source that at the moment is connected to the brake cylinder:


Any suggestions as to where the brake cylinder should be connected (I've noticed that the revs can be driven up by pumping the brakes when idling...)?
I should add that the engine is a 36D series from a Range Rover with an Offenhauser (360?) manifold and the previously mentioned 4-barrel Holley sat in a Capri injection special.
Many thanks in advance,
Tim.