Also you can contact Lars Grimstad in Colorado. [email protected] Lars may also be retired but he has written several papers dealing with all aspects of rebuilding, tuning and evaluating the Q,JET. All of his carbs were tested and tuned on his shop engine before being sent back to the customer. When I had my 75 Vette with an M4MC 800cfm QJet he was very helpful when I got into trouble with tuning. I still have a 750 Q" on my shelf that is a backup for my 440 if I need to work on the 3310. My spare came from an early 90's Dakota in a local salvage yard.