interesting in the linked ad for the Holley there is no mention of venturi or throttle plate size. I would think that would make a difference in how much air it would allow to flow. Braswell B-4825 Series carburetor is offered with venturi sizes from 1.40" up through 1.68", and throttle bores of 1.688", 1.750", or 1.790. Mine happens to have a 1.48 venturi/1.79 throttle bore. I don't have a 4500 intake fitted to my W8 so I bought a 4825 to play with in the mean time.