Volvo Repair: 1007 850, flame trap box?, spark plug wires, volvo name

Question
QUESTION: "Here is the question I had asked as well as the response from you Roger,  Subject:   850 Head question?  Question:   I just had the head rebuilt on a 1997 850 sedan and when the mechanic was all done but the VOLVO cover that goes over the head and spark plug wires are, he was concerned about a hole that was in the center that seemed to go into the oil chamber it had two smaller threaded hole next to it.  what is this for and does it need or should you plug it?  He placed a blue plastic plug into it and I felt I should try to find out if something should go there? Or should he not have plugged it?   --------------------------------------------------------------------------------   Answer:   John, Get a new mechanic.  That is a breather hole for the flame trap box.  A hose should be connected onto that hole.

Roger,
New Question: How does this mount, where does the hose go to,  and are there part #'s I can get?

ANSWER: John, The hose goes on top of the flame trap box and up to that hose.  I dont have part numbers here at home.  One thing I forgot to ask was is this an actual hole or is it covered.  There are 2 versions of this Valve cover.  Roger

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QUESTION: Thre is a recessed hole a bit smaller than a dime that goes in 3/4 to 1" thit has a bottem but it has a round opening to one side that opens into the upper part of the head.  there are also two threaded holes next to this hole.

The hole is in the head under the cover that has the VOLVO name on it.  I believe that it was between plug openings 3 & 4 going left to right.

Answer
John, If its sealed then dont worry about it.  If its a hole that you can actually see down into it and see oil then I may have to research it for you.  I would have you send me a picture to my Email but then too many people would have access to my email and would defeat the purpose of answering questions on this site.  Roger