Your going down the correct roads on the adjustments you've made
It ain't a six pack so don't over think two carburetors, which year carbs are you working with?
Are you up for using a wide ban O2 system to put the finest tune on the carbs that you can get? If so shoot for between 14.5 to 15.8 air fuel ratio at idle warmed up and between 13.8 to 15.5 on light throttle cruising below 2500 RPM in high gear and shoot for between 12.2 to 13.8 at WOT in high gear. The numbers I'm recommending are not the absolute best so test your car with your O2 system in your area on your fuel, you and your car may like fatter or leaner than the numbers I found that I liked the best on my last hot street car on Oregon pump swill