We were required to run a Holley 7448 (350 CFM) in the "street stock" racing class I built engines for about 20 years ago. A 355 cubic inch small block Chevy will run an absolute maximum RPM of 6100 on that carb before the venturis restrict the airflow enough to prevent any more speed- - - -regardless of the gear ratio, cam, exhaust system, or head modifications. At one time, I had a hundred hours or more of dyno time documented on that setup, trying to wring a few more RPMs and faster lap times out of it. That "350 CFM" carb was flowing 627 CFM at that speed- - - - -it just couldn't do it at the manifold vacuum Holley specified. My engines would turn 6500-7K, but they couldn't pass a detailed tech inspection. Fortunately, the tech crew was too dumb to catch how I was cheating- - - - -they even confiscated my carbs frequently- - - -and I'd take a brand new one out of the box and run the same lap times with it.
Jerry
