The Big Tow package has a transmission temperature gauge too, on an '04.
The Off Road package has the front skid plate, also, if it's a May build or latter, (and a 4x4) it will have the e-lock switch down by the tow switch. But earlier '04s didn't get the locker, and '04 2wd Off Road pkg Titans also didn't get the e-lock. All of the Off Road models came with Rancho shocks front and rear too.
Btw, you can download an owner's manual here:
http://www.courtesyparts.com/betasit...rs-manuals.php