Re: High Oil Consumption after Rebuild 4.3L Merc.
Could I test this theory by sending the hose exhause on valve cover to collection point?
I don't understand what you want to do there?
A valve cover baffle is a small metal box bow inside the valve cover, attached to and below the breather holes, the box has passages inside making it look like a rat maze, air and blow-by can get out, but oil is trapped and flows back into the engine.
I guess another way to test for a baffle would be to stick a screw driver in there and see how far it goes down, 1" or so means theres something in there (baffle) 3"+ and your hitting the top of the head, no baffle.
Pull off the breather hoses and see if they are covered with oil and look at the spark arrestor where the breather hoses connect, if you are sucking oil into the carb these have a lot of oil residue in them, they should normally be dry to having a thin film of oil, not dripping or really noticable.
And that's my SWAG for the day

(SWAG, I like that one, never heard it before)