It would be a waste of money for GM to develop a new V8 block that was physically larger and taller than the LS series. If GM did as you suggest, drop the OH valvetrain for OHC, there wouldn’t be a V8 aftermarket, or rather, a market of individuals who want affordable power.
Also, having a high RPM doesn’t indicate anything, it just shows how much needless reving the engine must do to reach peak. The LS’s haven’t had much difficult with greater accessable torque at lower RPM’s, and with torque values that come on stronger and sooner than comprible V8’s.
