650 or 750 Edelbrock on 340

I know I will get flamed for this.
Dan Nothing wrong with Champion plugs.
And
Dan a carb will only flow what is demanded by what it is on.
Putting to large a carb will not be better but can be made to work.
Say you need A 600cfm putting a 750 DP will not be good. But a 750 vac secondary like 3310 will work better out the box tgan a DP.
You gotta play with a way to large carb to get it to work.
He'll you gotta play with the right size carb some.
Are the rear blades open at idle? Right jets?
And as far as Holley goes best street strip carb to get working easy is 3310. It is more forgiving on wrong app. As is easy to swap springs and jets and is vac sec.
Much better than a 4779 in wrong app.