1971 455 big block

I'm building a 1971 big block 455 buick and I have everything but the carb and was wondering how many cfm's they came with. I have a holley 4010 series that's 750 cfm but I didn't know if that was big enough. If its not is there a website that sells upgraded jets for more cfm's

750 is pleanty big enough, even for over stock cams

For sure.

The stock Quadrajet on the w-30's back then were 800 cfm, 750 will work up to some meaningful mods having been done.