Those are all engine and emissions diagrams, the simple vacuum for dash controls come off the rear intake runner port.
Start a new thread, that sounds really messed up. Whoever carried out the carb swap obviously didn't know what or why they were doing it, which is nearly every carb swap.
403 olds intake vacuum checkvalve (2) by
Ben, on Flickr
403 olds intake vacuum checkvalve (1) by
Ben, on Flickr