2001 and 2002 trucks with the ETH/DEE options (see my signature) had the Cummins HO engine rated at 245 BHP/505 lb-ft torque (ETH) and the NV5600 6-speed manual transmission (DEE).
The standard output Cummins used with the NV4500 5-speed manual and the 47RE automatic was coded ETC and rated 235 BHP/460 lb-ft torque. If you have an automatic in a 2001, you have the ETC engine.
Rusty