I didn't say the engine was always under boost, it's a no-brainer that the belt is always turning (unless we're watching an episode of mad Max LOL..) or the turbo is always being blown through..
and my point was having full potential of the motor at all times without losing one bit of driveability and having extra horsepower on top for those extra rare occasions when you want it... Well nitrous set ups are not cheap they're nowhere near they are out a Roots blower would be for an engine like that. and keep in mind he's calling from a slant 6 in a 64 Dart to a 400 big block which is already going to be a lot for him to handle.. unless he plans on tubbing it for some tires to hold that kind of horsepower it's going to be ridiculous Overkill...