[Wbulk]

Was the air cleaner on it all the time it was at the body shop? Did you look down the carb and see if there was debris in the air bleeds? With the air cleaner off if you open the throttle quickly do you get a squirt from the accelerator pump?

So if it does run over 2,000 rpms it sounds like the idle and idle transfer circuits are the problem. Edelbrock has a good on line tech manual on how the carb works and explains all the circuits. There is also a You Tube video on taking the top of the carb off. I would take the top off. Take out the idle jets and blow through the idle jet holes and main jets with carb cleaner through the red straw. I would also blow through the air bleeds on the top by the venturis. Wear glasses so you don't get carb cleaner in your eyes. Cover your paint on the car or just take the carb off and do it on a bench.