Idle mixture or what? If you want everything else done, you'll have to buy a kit. Order the correct calibration kit for your model, I think its like $50 for their performer carbs. Is it there Carter copy carbs or Quadrajet copy? Anyways, you'll need an oxygen sensor. Edelbrock has a kit, as does K&N. Go to dyeager535's page and check out the link for an 02 sensor install. You can use a voltage meter on it or an 02 gauge from autometer to get your readings. Kind of a broad question.....