problem with holly double pumper carburetor

recently my holly double pumper has been acting up. on take off it starts to take off smooth then kicks real quick like it got no fuel for a second then returns to accelerating smoothly. it only does it on take off. it doesnt do it through any of the other gears. i rebuilt it with new accelerator pumps and power valves after letting it soak in parts cleaner and it still has the same problem. could it be a bad metering block or maybe the mainbody?