Here are a few '99+ body swaps:
LWB to SWB body swap bagged, build by (joey)
http://67-72chevytrucks.com/vboard/s...d.php?t=434253
LWB to SWB 4x4 on '99+ Tahoe Z71 chassis by fakerwade:
http://67-72chevytrucks.com/vboard/s...d.php?t=498570
And of course there is drews "frankenstein", crew cab conversion quad steer bad boy
http://67-72chevytrucks.com/vboard/s...d.php?t=426382
I am sure there are more out there too. enjoy