Image result for torque curve chart for 2001 chevy 6.0 engine
477 × 427 - rv.net
Graph pic doesn't want to post nor does the http address due to length. However, the graph shows the torque curve peaks at around 4400 RPM and approx 375 ft lbs or lbs feet. You should have plenty of engine output to easily tow 6,000 lbs in WV as the tranny will downshift as needed for more grunt. Assuming you have the auto tranny.
Peak HP is at about 5500 RPM
I don't have my engineering manuals handy right now but the numbers seem about right as I can remember.