I took two Edelbrocks off my dual quad setup and put to Street demons on... I've been inside the street demons several times getting the calibration correctly and they are almost identical inside. Both using metering rods and primary jets that are stand-alone to the street demon as in they don't have as many options as an Edelbrock. The Edelbrock / Carter has been around for all these years and has 50 different sets of metering rods and infinite amounts of primary Jets. Where the Holley Street Demon has about eight or nine sets of metering rods and 6 or 7 primary Jets in total.. and there are specific to the street demon.