The best adjustment is to pull them off and throw them away!!!
If that's not an option, the first thing you want to do is REPLACE EVERY vacuum line. That right there will solve a lot of problems. After that, Google "Nutter Bypass". That will remove the computer control from the carb.
Look into the Motorcraft 2100 carb. They make a great replacement carb, are super easy to set up, run better then Webers, pass emissions, and you get to throw out all but a few vacuum lines. They are pretty cheap too.