Check the front driveshaft...
..especially the CV joint right at the transfer case - which is basically right under the gas pedal...
8 bolts and you can get the drive shaft out to have it checked (or check it yourself) - you can also drive it to see if the noise goes away.
'97 TJ, 4.0, AW4 (yes, from a Cherokee), 241OR
Rubi 44s, 488s, Stock Lockers
Rubicon Express 4.5" Long Arm
Bilstein 5150s, 1" JKS BL, 1" ML
37 Krawlers for trail, 35" KM2s for street
Stretch and ORIs in the works!