I had an exhaust manifold stud out and sprayed brake cleaner in the threaded hole circled in green. To my surprise, the brake cleaner flowed out of the port circled in blue. I thought the stud was in a closed, blind hole. I also could see carbon deposits on the back of the stud. Does this mean the stud hole was drilled too deep and got into the exhaust port or is this normal for a 22RE head?