The weber could be the better carb. But the 4412 isnt really 500 cfm. Its identical in size to the front half of a 750dp (1.375 venturi, 1.687 throttle bore), so, 375? The correction factor to rate a two barrel the same way as the four barrels we are familiar with is to divide by square root of 2, that comes out to 354 cfm.
