600 vs 650 Holleys carbs in a dual quad setup?

[427LX]

In 1966-67 the 427 MR came with 652 cfm Holley carbs. At the 500 HP level in a hot street application is there that much difference between the 600 and 652 sized Holleys? The venturi sizes are the same with the 652 having the larger 1 11/16 throttle plates vs. 1 9/16 of 600's.  It also supposedly gives a stronger signal t the boosters so the carb guys say.

[BH107]

Not quite accurate. The normal MR engines came with BC/BD carbs which were rated by Ford at 710cfm. The 652cfm carbs were the C8OF-AC/AD carbs that were drag race only for the tunnel wedge intake. They aren't the best performing carb for the street, and don't have power valves. In any case, the 600cfm BJ/BK carbs are just fine for 500hp on the street.

[cammerfe]

Some 652 carbs are center squirters with EVERYTHING and were used in such road-racing applications as the 427/GT40s. They work GREAT on the street. (But not the very best for mileage.)

KS

[427LX]

So was the main reason for the 715 cfm carbs for the '66 and '67 427 MR,as in the 427 Fairlanes, mainly to legalize the larger carb for NHRA class racing? Interesting that the MR stayed at same 425 HP rating with the better heads and carbs.