your wanting a vent/brakeline tee bolt like 8 3/4s use. if I understand what you asking.

I think you could convert that over with the 3-port brass block/vent bolt from a 8 3/4.

you may have to change the rubber line from the frame hard line to the brass block port.

i will see if I can dig up the line/block vent bolt i have for pics.

after re-reading..i think you just need the vent bolt from an 8 3/4