2.8L bogging when secondarys open

:confused: Ihave an 85 2.8L thats been bored 0.060 over heads shaved 0.025 and a .268 172/164 cam in it with a stock carb. when i go full throttle it falls on it nose im not sure if it needs timmed or a new carb but it killing me at the track (23.55 @ 55.43 1/4mi) if anyone can help please do thanks.