I have a 340 AT w/Carter 4bbl in LeSabre. Car starts, idles fine and drives ok upon slow acelleration, but stumbles if gas pedal is pressed down hard and doesn´t "fly" as a 260hp car should (even with roughly 4,000 lbs.) Checking on the carb I found the blade of the primaries not opening completely upon full throttle. However, the lever on the lower part of the carb moves until it hits a stop. Here´s a pic, notice the position of the blade: And the corresponding position of the lever: I then found out I can manually move the linkage/rod to the carb blade further into the fully open position. See the position of the blade: and the lever: Knowing, that adjustments can be done by bending the tangs and rods, it´s hard to belive that those metals parts have moved about half an inch over time all by themselves. Any ideas what might have caused the problem and how to cure? FWIW, this part got busted, too, but I doubt it has anything to do with it?