[jhv48]

The street avenger has vacuum secondaries. If you want to maximize all the power your engine can make, get a mechanical secondary carb. The carb selector on Holley's web site even suggests a mechanical secondary carb for our light weight cars. I have replaced the street avenger carbs on both of my cobras (one had a 302, the other a 427) and in both cases, throttle response increased as well as dyno results.
If you stick with the SA carb, you're leaving horsepower on the garage floor.