[StanJ]

I won't comment on the recommendation you received from Carl, other than to say that we've never had problems getting a pair of properly sized and calibrated vacuum secondary Holley carbs to work well on engines of this type. Personally, I would opt for a pair of the Holley #8007 390 cfm carbs as a starting point. They'll require some recalibration, but nothing too complicated or beyond the understanding of the average gearhead. Venturi air speed would still high enough for efficient fuel atomization good throttle response, and also result in sufficient signal strength to the vacuum pod so that the rate and timing of secondary throttle opening could be well controlled.