Another edelbrock carb question!

Idle rpm is about 700 and vacuum in gear is 7" and 1973dusterkid, I originally had a 1406 edelbrock and went to the 670 avenger and couldn't believe the difference but it burned rich all around no matter how much I tried to tune it then I went to the 1405 which is calibrated for performance compared to the 1406 and was even more impressed over the holley. Plus I was always needing to mess with the holley I just want something I can set and forget.