The double pumper carbs are good carbs and would be a good recommendation if the car would spend it's time at the track. Because it is a track oriented carb. But that makes it way too rich in the transitions for the typical street applications.
All carb manufacturers make carbs that are track oriented and carbs that are street oriented. They do that because there is a difference in when and how much fuel needs to be delivered between the street and the track.
Here are a couple of articles regarding the Street Demon carb. And there are plenty of others out there if you want to do a search. I have installed Street Demons on several different cars and believe that they are the best carbs for mild street cars whose owners want a plug and play carb with good street manners.
http://www.carsillustrated.com/tech-got-me-one-of-those-double-pumpers-street-demon-carburetor/https://www.youtube.com/watch?v=jN2xbt6Mzdchttps://www.youtube.com/watch?v=DPOuEOkazVc
