vacuum line question on 351w

Hope someone can help me with this . I have a 1988 bronco with the 351 and I was hooking up the vacuum hoses on the tree and can't seem to figure where one goes. There are several on it including the brake booster hose which is the biggest one . The second biggest one is the one that I can't seem to figure out where it goes. Any help would be greatly appreciated. Thanks

He probably figured it out after 11 months. And I missed it when it was originally posted or I'd have answered. I don't think they were asking about the brake booster line, but rather the next one smaller. That is possibly the one that connects to the plate under the carburetor, on the back side. It is usually not easy to see. If by some chance that person still hasn't solved the problem and it isn't that connector, please attach some photos.