OK, I follow what your saying but peak HP is normally near the red line - not many dyno curves for the M112 engine but it feels that way to me. Don't know where the cams come into this...but never mind, unless it this, the power drop that occurs at high rpms is because the VE (volumetric efficiency) of the engine declines at higher rpms, but the decrease in VE means less air is going in (per rev), less air means less fuel required, so duty cycle doesn't keep increasing in a linear manner with rpm?

During acceleration the AF needs to drop from 14:1 and that acceleration enrichment will increase the duty cycle even if the rpm hasn't maxed you might get to 100%. Say it goes from 14 to 12 that's a 16% increase in fuel.

Basic point is to get 215 hp you need to put enough fuel in (and the figures are usually for 14:1), that makes the injector cycle 100%'ish for 215 hp, - end of.

Power in the mid band, on acceleration might be improved with a small increase in injector size, I think tip in would be adversely affected by SRT injectors, if the engine started at all.