Why he's doing it is irrelevant, he is doing it and that is what he's asking. Stock 73/74 setups apparently will not work with his combo and he's asking what does. I don't have a setup like what he is using and googling around doesn't show a brace on the compressor on any of the images I could find, 68 Charger 383.
PS, stock choke won't work right with an AVS on a spreadbore intake with an adapter.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.