I have a 3.4L, 5speed, 35's and 5.29's and have no problem accelerating.  Usually cruise around 65mph all day long.  when i get to about 70 im around 3200rpms, right in the power band, sucking gas.  So i try to stay slower than that.  Its nice though, hills arn't an issue anymore and it straight pulls.

Right now im rolling on 4.10's and on the highway speeds it is much better. hills, well not so much. I think right now on the 4.10's crusing at 70mph im just above 2500 rpms.