New head with unknown port near back of head
I acquired a rebuild head which seems to be 1975 vintage so it's a newer style. I was hoping to install it onto my 67 225 6-banger but I noticed an extra port at the back of the head. Can anybody tell me what this is and how do I plug it? See the images below.
I acquired a rebuild head which seems to be 1975 vintage so it's a newer style. I was hoping to install it onto my 67 225 6-banger but I noticed an extra port at the back of the head. Can anybody tell me what this is and how do I plug it? See the images below.
