Forget the stock manifolds as that would hamstring that 465 hp motor. That level of hp from a 408" motor requires headers and a good intake. Take away those parts and you will end up with a less than happy combination. You can still make it look stock'ish without giving both of those up.
Have you considered EFI and overdrive? If not, drivability will definitely suffer. For cooling, a custom US Radiator will do nicely.
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