1972 Demon 340 engine mods

Now its time to do something about carb on the Demon.

Car now has 80508-2 Holley which is vacuum secondary 750cfm. I finally had a chance to drive it a bit longer and adjust this carb idle etc.
To put it short, I hate how it works. This 340 should like to rev and should have nice throttle response, but has none of that. Its sluggish and there is really slow throttle response, 4000 rpm feels like an effort...
This carb as used with spacer or previous intake, I don't plan on using it.

I have Holley 0-4779C on the shelf and am tempted to use it. It has 75 jets on all corners which is probably way to much of this car right now. What jetting would you guys suggest to start with? I was thinking 72/75 or 69/72?
Will also check vacuum to see what power valve to use... Boy this will be fun. I will put my o2 sensor on the car to make my life easier.


Use it. Vacuum secondary carbs are boat anchors.

Flame on but I detest VS carbs. If you bother to check I'd bet the secondaries either never fully open or come open so late it's worthless.