[Skinny Kid]

It's true. My q-jet in my 71 is the best driving carb I've ever had. I've had Holleys that drove awesome but, all around the q-jet takes it. 30 degree cold start, one pump start and go. No issues at all.

You can take a 2 barrel and tune it on a 6 cylinder the take it right off and drop it on a (mild or stock) big block and other than setting idle settings it will be pretty close. Too small of a carb won't cause you to run lean, it will just limit power and rpm potential. For a lean condition to occur the engine has to have inadequate fuel for the given air flow. If the air/fuel ratio is correct, regardless of CFM, you won't run lean. A properly sized carb will perform well all around though. Too small and the power and rpm are limited (way too small there will be other issues), too large and it will have poor drivability and be lazy due to a weak signal. Correctly sized and it will have a strong signal, be responsive and run well up top. That's another area the q-jet shines. Small primaries for a strong signal and great drivability, large secondaries for power and the air door only delivers what the engine can use. An 850 q-jet for a big block will run just as well on a stock small block if it's set up right.

CFM is not the end-all though. I ran my 750 on the Chevelle 383 because that's what it liked best. It didn't need that much at all. For instance, I run a 1050 Dominator on my 422 small block in my 67 Nova. It turns 8,200 rpm and runs in the 9.10-9.20 range in the 1/4. I run the car in c/gas which is a 9.60 index class so to slow it down I run a Dedenbear adjustable restrictor plate underneath and you would be shocked to see how much I have to close the plate to run a 9.60. I've never flowed the plate to see, but it has to be in the 800 cfm range or less. I can't insert a pic of it for some reason, but it looks like a cat's eye.