STREET AVENGER CARBURETORS These carburetors are designed to run right out of the box--tunable from mild to wild! The first true performance carburetor designed, dyno tested, street proven and calibrated specifically for optimal street performance Square bore bolt pattern Holley's No Trouble ™ design allows you to just bolt it on and go! Many years of engineering and testing go into each Holley Street Avenger Carburetor to give you maximum performance in a street friendly product. Precise fuel metering for monster low-end torque, awesome acceleration and unmatched to-end horsepower. Tunable air and fuel idle provide crisper acceleration. No Trouble ™ electric choke provides a cleaner, smoother warm-up in all temperatures. External No Trouble ™ float adjustment can';t be mis-adjusted-;keeps the street enthusiast out of trouble and on the road. Not legal for sale or use in California on any pollution controlled motor vehicles.