[davepl]

Here's my Q-jet one. As you can see the line from the valve on top goes to the inner port, the line from the carb to the outer port, although it's not connected in the picture.

That's different from the guy above but I'm pretty sure it doesn't matter, it's a vacuum switch. You can check the factory assembly manual to see if there's any detail in there...

If yous is different yet again from these two I think YOU need to post a picture, it might not be original to the truck or something.