Even if it physically fits, the instrument cluster will not work; the 1st Gen and 2nd Gen LS PCMs use different protocols. 1st Gen LSes ('00-'02) use OBD-II; 2nd Gen LSes ('03-'06) use the CAN protocol. The computer modules, including the instrument cluster, are not interchangeable between generations.
Edit: It looks like he's asking about the interior parts, not the electronics. I don't know what trim pieces, if any, will fit, but I would be surprised if many do (the changes are subtle in some ways, but subtle changes can be the difference between fitting and not fitting). The electronics are pretty much a universal no-go, though.