A DP is the last carb you need on the street. It'll suck fuel like no tomorrow. Every time the pedal moves they shoot fuel on both sides.
Wrong... The linkage is still progressive. Stay out of the secondaries and you'll be fine. I daily drove my dart for years with the 340 and a 4150 750. The car ran [Email]12.30@107[/Email] and would get 15MPG @3600# with 3.91 gears and 26" tire. BUT, I dont think the carb is the issue, its probably multitude of things making this a mismatched/ underperforming combo.
The OP needs to weigh that thing before we get into too much detail. Yes MPH seems low, but that car could be pretty heavy which would explain most of that.
BINGO!
Drive a DP with any sense of what you are doing and mileage is not an issue. If you have a lead foot and always mat it from a light, mileage will stink. It's all in the right foot.
13.60-104, 20 mpg on the highway with a 4779 750dp. It got 14-15 around town...
My guess, OP needs to fix the initial timing, bushing, springs FIRST! Don't do anything else until you get that sorted out.
Vacuum carbs easily give up 2 tenths at the track compared to a DP.
