Carburation is dependant on a lot of things other then just cubic inches. The cam and valve train, cylinder head runner size, and intended usage are just some of the factors. For example, a 460 with a mild cam in a light weight street car with a 750 vacuum secondary carb will work fine in a light weight car on the street.... Then like my old trusty solid roller cammed 408 Windsor cammed engine with almost too big of heads, and a 5 speed takes an 800 (flowed to 830) mechanical secondary carb to pump enough E-85 through it to make it run really strong.....

My observation on Hot Rods has also been that the 2 biggest mistakes are over-cammed and over-carbed engines.... Bigger is not always better....