This type of info is too limited to be of much use, IMHO. This is probably just a peak HP number; no info is given about the effects at lower/middle RPM's, and what the actual limiting factor was for peak HP.
I agree the hp curve matters more than peak, but highly doubt it’s making much more than 5 hp down low, especially when the restriction of the manifold gonna more at higher rpms. There’s little reason to put on expensive 340 manifolds when 360 or even magnum manifolds are gonna give you 95% of the power for lot less money.