I know it's apples vs oranges but we had a blown small block in a door car with zoomies, went to a 434" stacks injected engine both on alcohol and tried the zoomies for a couple weekends. I too love the sound of zoomies. O'k changed to 2" 34" primaries with 3 1/2 collector, picked up .15 the first time out and a little more after a little tuning, the car actually needed less fuel and ran faster with the headers.
Zip.