My buddy just bought a 2000 I think, and he's taken it on the beach(seaside park and ibsp) about a dozen times. He's happy, but he's gonna blow his tranny. I tole him to drop the tire pressure to 15, he said 17 was ok(scared 15 is too low) and he digs some deep tracks when he's on. This is also with standard size tires. I'd say with a 3" lift and oversized tires, you should be fine.
1 owner, no tow package (I'll install that) so it hasn;t been worked too hard, well maintained, and looks very good for it's age. We'll see how it does.
the only problems these have with trannys are the people who neglect or abuse them, and thats true for all manufacturers. To the person who said they had to replace it twice... thats probably because they didnt flush the cooler and there was still crud stuck in there. however i will say you will probably have to replace front wheel bearings and tie rod ends, I do them alot at my shop. JUST TAKE CARE OF IT!!! a well maintained vehicle should not give you any issues and if you need any help just PM me. I am a chrysler certified tech and have access to stuff private shops dont. Have fun with it though!