The Pontiac (Chevy) 230" used a QJ, why does it need to be smaller for a 24% smaller engine? w/r/t cruising CFM: assuming the mixture matches, the CFM used will be the same regardless of how many throats. Depending on the venturi type the manifold vacuum could go either way. Disabling 1 primary barrel will also have another effect: the operative throttle blade angle will now be higher (more rotation) in the throat, and the idle/transition slot relationship will change quite a bit. If the blade is above the transition slot the tip-in response relies on pump shot. The usual cure is a small hole in the disc right next to the slots to allow air to enter with a smaller angle.
