New Holley 1920 Needed

No, it will not need gaskets or other stuff. I've done this enough times with enough NOS carbs to know it will run just fine (and keep the gasoline on the inside where it belongs) without a teardown. Use an unbent paperclip to gently push the inlet needle away from its seat (they tend to stick when sitting for years on the shelf), shoot some light oil (Liquid Wrench or Blaster) into the bowl through the internal vent pipe and operate the throttle a dozen times to oil the accelerator pump plunger, drop the carb on and off you go.