340 problems

Do you have a throttle return spring? Had that issue on the Dart Sport and all that was wrong was that the butterfles were open just enough to mess everything up. My timing was similar, swapped carbs as you did but had no double return spring to pull pressure to have it closed all the way. $ corner adjustments were all 2 out, and Idle screw was maxed out. Keep updating please, this is a good one.