From a 2002 1500 4X4 Silverado Manual.
The manual tells you to pull the IGN 0 fuse in the Instrument fuse panel
on the drivers end of the Instrument panel and turn key OFF.
If it is a 4X4 put the Transfer case in neutral when flat towing.
Could be just the difference in the rear end gear ration.
My 02 1500 Silverado LT 5.3 with 4.10 gears is much faster/quicker than my 00 1500 Silverado LT 5.3 with 3.73 gears.