Street Demon tuning experience
I have that exact carb on my 1973 Dart Sport 340 . It has the original 340 engine with a stock rebuild. My Street Demon experience is the complete opposite of yours . I bolted it on new in 2015 , set the choke and adjusted the mixture and idle screws and have not touched it since . Good cold and hot start , crisp idle and great full throttle plus a consistant 15 mpg . The reason I went with the Street Demon was the appearance was similar to the original thermoquad but most important was because of the heat soak , vapor lock issues i was having . Worth noting that I live in Florida , and could simply not drive the car on any day over 85 degrees with the old avs carb . That issue was instantly eliminated with the installation of the Street Demon and I now enjoy my car no matter the outside temperature.