[XXX4life]

i have a vaccum line with vaccuum and i don't know where it goes? this might be why my gas milage sucks, so i swaped a DOHC into my SOHC car and my friend re routed all the vaccum lines and said they were all hooked up and accounted for then i get the car running and one of the lines has vaccum still? but i don't know where it goes? if i plug it the car dies? if i leave it open as i have been it's idling high, so the only thing i can think of is that it's gotta go into the intake manifold somewhere? anyone have aany ideas?? thanks