Well I see on the 3W site Aircraft International that they offer a carbon fiber intake manifold (actually it's a banana shaped velocity stack) that fits inside the cowl on the bottom-carb motors. They hook the diaphragm metering tube up at the elbow of the stack. It might be good for some more rpm as well as fixing the mixture problems in the midrange that some (?) of the 3W twins have. Only (?) $40. Let's talk Tommy into spending his money.q;}