There is a thread on actual cfm of the Carters. From what I remember of the later ones, they were larger in cfm.
I don't see how the missing choke linkage as well as the reduced area from the counter wieghted air door to the spring loaded air door add up to that much.
I spoke to an Edelbrock tech when i bought my 650 Thunder and he told me there were many changes
made internally to the new Thunder series and they flow better and higher than the older models.
