20v water galleries

[road rally]

Help needed please, i am currently in the middle of fitting a black top 20v into my ae86 and need some info on the water galleries on the back of the head,not wanting to cut the bulkhead have checked out the chita type kit what i need to know is there are two waterways does the waterway on the inlet side on the back of the head get blanked off as the pictures of the chita conversion back plate seems to show or is there or has the back of this plate been machined in some way to allow the water to travel between the two galleries, any photos or info would be most welcome