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I see a vacuum line missing from the check valve going to the cruise control.
If you can't find that tube in a yard, it should be fairly simple to either fab one up, or braze yours back together.
Run a search for Dorman 46001. Is that it?
Fabricate it out of 1/2" soft aluminum or copper tubing and paint it satin black. The missing vacuum line should connect the check valve at the top of the image to a single port manifold vacuum tree located behind the TBI assembly adjacent to the ignition coil. It might behoove you to make a thorough inspection and look for any other problems introduced by the smog shop.
if you have good relationship with a GM dealer parts man,Part# 14102133 is the number of the tube. There are about 10 dealers in the USA that show to have it still. Have the parts man call one of these dealers and see if they will sell it.
If the local dealer doesn't want to arrange procurement of the part for you, (s)he should be able to provide a printout for the part that shows the "other" dealer addresses with phone numbers for you to call and arrange purchase directly. Request a physical stock check and verify the selling price including an estimate for shipping. A handful of dealers are quite proud of their "obsolete stock."