this is the diagram that ryguy sent me:
the red line shows the new vacuum line path after you connect the lines that go into the top of the egrc-bpt together. you can see the lines going into where they're supposed to on the bpt valve right underneath the vacuum "rainbow" lol... im attaching a closeup of the original scan from the 1991 FSM so you can better see where the lines attach to the bpt valve