You're correct. The only point I was trying to make is a cube in one motor is not equivalent to a cube in another motor. But your point - I think - is that an extra cube in the same family of motor is almost always an advantage, which it is.
And I should know better, as I've just built a 331. It will likely make a lot more power than my 289, that died beacuause of a "performance" distribrutor/oil pump shaft that sheared off. This time i'm using ARP but the diameter is so small (one of the horrible design features of a small block ford) that I don't even know if the ARP will hold up.
I just hope I didn't overcam it, I used an Edelbrock RPM cam, which has a little more duration (224/234 at 0.50) than most cams that are routinely used in 331 and 347 to make 400 HP. Remember, for a street car, better to err on the side of less cam.