I've got a balanced 454 with large oval port heads, single plane and high-rpm cam, headers and duals. I would like to stay with a single 4-barrel, what size cfm should I be looking for? I have an Edelbrock 750 and a Holley 750. The Edelbrock seems to not be able to feed it enough no matter what I do. The Holley works well, but I am concerned that it is not getting enough fuel for optimum performance still. My 750 is a regular single feed vacuum secondary model. Should I go double pumper 750, or larger, like 850 or 950? TIA.

This is a formula I just read in CC take motor size times max rpm's divided by 3456. So example.
454 x 6000/3456= 788 cfm carb. Of course this is just a rough estimate.

800-850cfm. 950HP is popular here, 830 annulars are NICE for street/strip apps.

Your 750s will be fine for the street, but you say " high rpm cam". Theway I checked was to watch my vaccum gauge. As the motor crossed 6000 rpms, vac was increasing and got close to 5" at the shift point, ergo, 750 was too small for 6000+.