I think my 4.0 was louder, but it was very old. The turbo whine stands out. The first time I had it around my dad he said that wasn't a diesel. My 5.9 common rail is definitely louder, but not in the cab, but it's got sound deadening and insulation.
I just find TJs and older Jeeps to be loud in general. I've always driven with hearing protection or something to knock the wind noise down, but I'm kinda weird like that. I wear hearing protection on a road bike, because I can't hear anything with the wind, but I can with hearing protection.
Something else that was mentioned somewhere about heat around the transmission, I added a 1" BL when I swapped my engine, but when I just pulled my transmission I added some of the Noico heat or sound stuff around the bellhousing area in the tub. I did a few long drives on some hot days and my floorboard is much cooler than before the swap. It wasn't really hot outside before I pulled the transmission, so I'm not sure if it's the BL, or the noico stuff.