(1) Welcome to CT!
(2) I'm not aware of any changes to the frame that began in 2001. There's no mention of frame changes in the 2001 model year "new features" documentation, and the factory collision repair specs for frame locations and distances are listed for all years from 2000 through 2004.
The 2001 - 2004 models (other than the S-Runner) sat taller than the 1995.5 - 2000 models, but this increased overall height resulted from different tires and suspension components (e.g., shocks and leafs).
Bottom Line: I can't absolutely prove there's no difference from the available factory documentation, but I can't find any clues why a lift kit for a 1995.5 - 2000 5-lug Taco wouldn't work (and install the same way) on a 2001 - 2004 model.
Performance Accessories appears to be the source / manufacturer as well as the vendor for the kit. I recommend you call them and ask if there's a reason the 1995.5 - 2000 kit wouldn't work on your 2001.