Rated at 310 hp or 320 hp depending on fuel
Was the first year of the last variation of the 5.4l 3V engine.
Only made in 2009 and 2010
Replaced by 3.5 V6 Ecoboost or DOHC 5.0l Coyote for model year 2011
Squeezing more power out of the same modular engine was only done with a blower.
The block and heads (and engine controls) were changed to make the happen.
And then only done on the 5.4l 4V.
Got hp ratings up to 540.
Ford (and most other companies) spend big bank to develop an engine family.
For the last several decades there wasn't as much pressure as there is now from the Govt regarding fuel economy and emissions
There is natural aspiration and forced induction. (Turbo and super charger) The forced induction will get some more power if the design is strong enough or the design allows some strengthening.
So, the modular engine family (and other engine families) have a theoretical limit as far as how much power can be obtained. Once that is reached a new design is needed.
The modular had run it's course by 2010 or so. Both in NA form and with a blower.
There might be some things you could do to get 5 or 10 more hp without forced induction. But even that you are going to spend money and there may be some running conditions the engine has issues. In addition power train packages (Engine & transmission) are integrated. Meaning everything is controlled by software programs that are set up to sync everything together. Change a piece in one area and the system has an issue because it does not recognise the change without electronically making changes too. All of that can be done and it gives me a headache.
It's not the 60s anymore
The industry is in transition. Gas and/or battery. There is a lot of government pressure (and money) to move to batteries.
Once the money goes away (and it will) will batteries stay in significant number to sustain sales?
Long time ago steam power was a thing. It just was not sustainable.
Want more power?
It is far easier to pony up to a modern designed one.
Or buy a ride from pre-72 (or 68) and knock your socks off with mods.