Bought a street avenger carb idle is at 1900 help

vaccum leak?

Is your throttle linkage allowing the throttle to easily return to idle position?

are your lower butterflies making contact with the lower manifold or possibly a gasket in there allowing them to be held open?

I ran a Holley 570 SA in my car trouble free, straight out of the box; my suggestion would be to check all the easy things first... the simpliest things get overlooked very easily sometimes.
 
i dont have a carb'd car to look at here at the house, but isnt the throttle return spring supposed to go twoard the front of the engine to pull the throttle back to idle? :shrug: