Pro4x / off road package final drive & rpm/speed?

[Seranin]

Someone educate me...I searched for a while but did not come up with an answer

I'm considering a 2008 Pro4x that's at about $30,000 with the current rebate but am wondering about the advertised lower final drive ratio... this would mean a higher engine rpm at a given vehicle speed, right?

Can anyone say what rpms Titans are at at, say, 65mph... a non-pro4x vs. a pro4x? Love everything else about the truck but don't want to get stuck revving the truck all the time as many of my miles are highway ones...

Also - does the locking rear diff make a noticeable difference, or are people still swapping out for the Truetrac?

Thanks!

[ElevenTenths]

65 mph ~1800-1900 rpm on a Pro4X.
Same final drive as the "big tow"
e locker works but only in 4 low and only up to 4mph (same unit as the lighter xterra uses)
Detroit TrueTrac is a mechanical limited slip unit, not a locker