It really depends on how you build the V-8. My old f250 had a stock 390 in it that made a whopping 375 ft./lbs. at 1600 RPM and 200 HP at 4200 RPM. If you build a stroker with an RV cam you can get 300+ easily below 3 grand. Most V-8's don't actually turn that many RPM's. Usually I see torque curves kicking in round 1.4K and peaking at around 2500-3500 on a V-8. If I were to swap in a v-8 just for torque I would really consider that 390...
But then again, Why??? The engine makes more than enough power to do anything a jeep is meant to do or good at. I personally think that a V-8 is too much power for a short wheelbase near stock jeep.

The 4.0 makes 220ft/lbs at 2500 RPM.