The devil is in the details in the balance of the motor build. I have seen the opposite when comparing average hp in the shift-to-shift recovery rpm range.
I edited my post earlier because I didn't format my sentences very well, then I completely forgot to add in the fact that " my smallish camshaft" responded well to the tighter lash.
There's the devil in the details.
That cam is 264-268 @.050 in a near 13.0:1 470 cubic inch low deck.