Pulling V.A at idle

I would pull the carb , flip it over and set the T-Slots first. Then set your initial timing to whatever brings the rpms to what you want (700 ish). Then reset your idle screws. If it still requires 3.5 turns out you may need to enlarge idle air bleeds.
I didn't, when I set em, was me n a Vacuum gauge, some many years ago, but was points, and a heavier car then