Bog or "flat spot" can also be from lean-ness in off-idle situations, not always accompanied by a "spit-back" through the carb.
On a metering rod carburetor, when the rods stay in the "down/economy" position as the engine needs more fuel, "no power", by observation. IF a 4bbl, "power" will happen only when the secondaries start to open.
By comparison, the Carter/Edelbrock accel pump nozzle is "slobbery" compared to the more precise Holley shooters. No real way around that that I've found.
CBODY67