The "Off Road" is an order option on the 1500 Rams only, and includes 17" wheels and other trick stuff.
I think the camper package does jack-up the rear end. I believe the regular rear springs are the same, but the overloads get stacked in there above the axle increasing the truck's rear height. I don't think the trailer tow package does anything to ride height however.
The snow-plow prep does provide different springs on the front, but may not change the front height (i. e. , stronger springs but same length) except when the front-end is loaded with additional weight. Someone told me this, but I don't know if it is true or not. They said only way to get the front-end higher is with a minimum 2" lift ("leveling kit").
The snow-plow option is blocked in combination with other options (I think with the SLT plus). Was that way when I ordered.
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Just got my 2001 2500 QC, SB, 4x4, ETH 6-sp, 3. 54 LSD, SLT++ (everything but those lights on top of the roof), White over Silver, Tan leather. Picked it up 8/31/00.