That is correct Sir. Been there done that doesn't fit under the hood of a '73 twin scoop Cuda.
Also agree on the 302 heads. The 360 heads are better for the task at hand.
400 HP can be made with a Comp 280* Magnum series cam. (Not Dodge Magnum, read roller cam) Well preped heads will do. Bowl porting insures performance based on the year head you have/get for this build.