With a Holley 750 vac secondary, I can't emphasize enough how having the idle/transition circuits tuned just right can make a HUGE difference in your overall quality of life.
Seriously, the idle/off-idle/transition circuit is really important when you're just driving around town, at low speed, and gently accelerating. It's the difference between the carb being "just ok" and it being great. And to get that circuit just right, easily, you replace the hidden screw on the underside of the carb, that controls the opening of the secondaries, with a 25 cent mod like I have right here. You then adjust your idle RPMs with a little Allen wrench. That screw, btw, is 10-32.
