[olddog]

I'm not sure if 1450 is a model or the CFM rating of the carb. If it is CFM, it is too big in my opinion.

456 cid spinning 8000 rpm at 100% efficiency will only suck in 1050 CFM. Most engines cannot achieve 90% pumping efficiency. That said it is possible to tune cam, ports, intake and header lengths to achieve way over 100% in a narrow rpm window, but race teams spend countless hours on a dyno to do it. Assuming your engine is not at this level, I would think a 1000 cfm carb would be plenty. 850 cfm would be enough for 6800 rpm.