Originally Posted by houston

they are basically air/fuel ratio mixers , think of it as running anywhere from lets say a 325cfm carb (6mm) on your 454 big block (power loss for sure) , but it will run efficient with excellent fuel mileage . if you want more power and more fuel consumption use a 1000 cfm carb (9mm). granted there are a few more variables on these big block nitro engines we love so much but that should put it in perspective i hope