4846S Carter Thermoquad Competition Series Carburetor 850 cfm

Mechanical top makes no sense. The secondary butterflies do that. A secondary pump shot is not necessary on a TQ. If the air valve is adjusted correctly, you get no bog and the dumping of gas to compensate for it, like a Holley. It is also why they are forgiving, being able to be adjusted for a wide engine size and rpm range.