I've messed with these q-jets,,, the cfm war isn't fair on them,, there are basically two types of bodys, 750's and larger 850 and up,, you can tell by the bump in the venturie, big bump = small, less of a bump = larger version, but the q-jet is basically an air pump, it will feed the amount of air any givin engine will demand, the trick is supplying the fuel for that demand, thats why we see these carbs the '750' version on anything from sixes to big blocks,, the fuel is supplied thru the metering rods and jets on the primary side and a set of quickly changed secondary rods,, the trick (or gigantic headache)is the speed and travel that the secondary flapper door opens,,(the choke looking thing on the secondaries), it is adjustable by a hidden spring and a set screw set into the body for further adjustment over the factory tang,,,typically the door flapps open way to fast,, and that is the "bog",, if adjusted properly it will kick in smoothly,,,
There is a turbo piece for the q-jet,, if your carb has an APT,, you need to make sure the base plate does not have the vacuum orifice to actuate it in a certain position, I fought this forever in a non turbo app,, I had swapped basses for linkages and fumbled for months,,Cliff Ruggles clued me to this,, great rebuilder,, and wrote a great book if you get into these carbs,,,
