My 3.0 is not fast -- but I can do a lot with it.
You can help it a lot: intake, maf change or mods, throttle body change or mods, exhaust, headers, roller rockers, cam, flash tuner -- in various combinations.
It's an old-school, fully cast iron, pushrod engine -- what's to be expected!
On the other hand, care for it and it will last forever...or at least it will seem like forever...
Seriously though, mines not getting changed out until it dies.