IIRC the turnaround time averages 4 weeks. Had to send mine back last year sometime when I junked it and got it back in 2 weeks but they said to expect more. I think that it varies based on where they are in production / how many orders they have coming in. If you call them and ask someone they'll give you a (more) definitive period. They're usually pretty good to work with.
What's your rack getting rebuilt for?
Wrecked and rebuilt even better
289 v8, 4-speed, 3.25 9" rear, goodies and stuff.
Currently road tripping - 7 weeks and 9500+ miles! See the travel blog here: http://calamityjaneroadtrip.blogspot.com/