I have flushed the radiator, replaced thermostat, fan clutch, belt, belt tensioner and still after 20 minutes of driving in Florida the fan clutch roars continuously.
after new fan clutch and thermostat, fanclutch starts roaring within 20min. on 2000 Dodge Dakota
I had a similar problem with my '97 V-6. I know you said you had just replaced the fan clutch, however that was the problem with mine. The clutch is supposed to keep the fan from running at the same speed as the engine. Try this: start the truck and let sit for a minute to warm up, then rev the engine a little to see if you have the "roaring". If that is the case then your clutch may still be bad. Make sure that you did not ruin the fan spring on the front of the clutch when you installed it.
I am now on my third fan clutch. The entire winter here in Fl. has been un-naturally cool. The fan clutch never once roared. Its now warming up daily and the symptom is back. Did I mention that the temp guage still reads below the mid martk. I am ready to pull the fan clutch completely and install something else to cool with as the electric fan in stalled is not strong enough.