Edelbrock part throttle surge help

Stock is 7/16 I thought. That's where I set it via my instructions. I also. Checked for vacuum leaks around the base plate all hoses and the throttle shafts. I didn't find any. I'm going to have to buy the tuning kit for this carb. It's too bad. This carb is super simple that's why I like it so much, but I hate these little problems.