Where's the Rocker Pedestal on 1967 440 915 heads

Those are the smaller port heads. Someone had swapped them onto my 68? May have been original but I doubt it. Some guys, would not sell their good heads with a car or motor. Any 68 up heads will run better than what you have. Even if you take a loss in compression. 383 pistons do not sit as far down in the hole as 400's and 440's. Even with 516 heads you should still be pretty quick with a 383 in a 67 Barracuda?