Gas Mileage query Holley 318

The Street Demon is a good modern "replacement" for the Thermoquad, I have the 750cfm version on my 360 but they also make a 625cfm one. I like TQs but these days it's hard to find good cores and parts, plus you need an intake with a spreadbore flange which there aren't many of those around.

I'm actually looking to switch over to a Holley DP-style carb because my Duster is gradually becoming more of a weekend warrior than a street car and gas mileage isn't as high of a priority as it used to be. Not that you can't get good mileage with a double pumper it's just not as easy and doesn't adapt well to changing atmospheric conditions like a Carter/Edelbrock or the Street Demon. There's also the new Edelbrock AVS-2 that comes with annular boosters in the primaries which should be great for gas mileage and street driving.