I think you are thinking backwards on that, #7 is the hardest cylinder to get the mixture correct on a single plane intake with one four or two barrel carb work
#5 intake runner and intake valve are closer to the throttle blades also work
Put a tunnel ram on it with two Dominator carbs and forget about it whistling work scope up twocents grin

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)