Dear all, i have replaced my cylinder head since i saw that it was not worth repairing. After few port and polish i assembled the head and start the engine. There was loud sound and smoke, when i checked the engine i saw that there is a port (hole!) at the back end of the head, just after the exhaust manifold. There is only one tapped hole for a screw and a port that seems to be open to exhaust.is this a sensor place or, what is it? My old previous head did not have it, maybe something changed in newer models? Heeeeeeelp, i do not know what to do

That is where the tube from the AIR pump attaches. In your gasket set you will have a somewhat tear-dropped shaped gasket with a couple holes in it. Use it as a template to make a cover out of 3/8" plate and bolt it on. Blocking the hole will hurt nothing.

You could also drill and tap it for a pipe plug.

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Official Cookie and Mater Tormentor.

I have just cranked a pipe plug into the hole.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Please see here for full info on this port.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I am very happy to get answers this quick. You all have been a great help, thank you. Today I will tap it and bolt a plug in. Thank you again.