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The 4180 on 460's was rated @ 600 cfm,
I believe the 4180's in the 5.0 mustangs were 580 or so.
There's even a 675 model.
Check the #'s, I think there's a sticky on the fuel delivery board.
Engine size can effect the flow capacity of a carb. Example, back in the early 60's the 406 and the 390 both had the exact same 3X2 barrel setup. The 406 was rated at 920 CFM while the 390 was rated at 860 CFM. This is the auto manufactures only. The rated CFM of a carb from most carb manufactures is 4 barrels are rated at 1.5" hg (vacuum) and 2 barrels are rated at 3"hg.
With the same engine CID at the same WOT rpm the the 2V engine will have a higher vacuum than a 4V will because of the smaller cross sectional area of the throttle bores and the venturi areas and that's the reason as told to me many years ago by a Holley tech guy at a Nationals drag race in Tulsa.
Thanks Bear,
This makes some sense, but logically one would size the carb to displacement, and rpm range unless restricted by race rules.
Guess I'm too ignorant to think this way, and had figured manufacturers would compare 'apples to apples.'