1968 Match Race '383 Road Runner' vs 'Cutlass 350 Ram-Rod'

Why is the 383 such a stepchild.
It seemed that if you were replacing the engine in your Road Runner back in the day, most everyone put a 440 in it.
Why is the 383 overlooked as a performance build-up by most. Cubic inches?
I have been a small block guy for the most part, but have built a few 440's for customers & even ran one in my S/ST Duster.
The 400 (block) is more popular than the 383.
I do have a friend that runs a SuperStock Cuda with a 383, he told me that it dynoed @ 750HP.
I know thats a SS engine, but that seems like good numbers to me.