The 71 TQ was known to be difficult to adjust, if you had problems back in the day and went to the dealer for a replacement you would generally get a 72 TQ as a replacement. This particular car is not my car but it is a survivor. The story that surrounds the carb change is thought to be because of a small carb fire early in it's life, the carb and a few other minor surrounding parts were replaced and it a part of the intake was spray bomb touch upped. Other than that it's exceptionally original under hood.