You are talking about 43 less cubes. Your problem is your thought seems to be that similar top ends should make similar power on a 408 or 365. When someone starts to explain why they don't you ramble on about how the smaller motor shoulda coulda woulda if the ports were different and the cam timing is changed. That's not a comparison. Define the parameters that you feel should differ between the two engines to make them make the same or similar power and maybe someone can agree or disagree from there. This is a go nowhere endeavor until you acknowledge that you are in it for the debate/entertainment rather than the education.