my buddy had a 318 dakota with a 4 speed auto with some bolt on stuff-headers,pulleys ,computer,no big deal- IT GOT 12 MPG
he also had a longbed 76 dodge with a 440- IT GOT 12 MPG
i have yet to see a computer setup that does an overwhelmingly better job at mpg than carbs.
I have a mechanic friend (a real mechanic, not just a 'parts-installer') thats a Holley guru that would agree with you 100%. I'm still not sold, but i'll concede that if everything is running/tuned perfect, the carb could at least be damn close. There are some pretty damn smart builders/tuners that still dont like EFI... even for MPG.
