Before you get rid of the 203, make sure the 208 is going to fit. The adapters and bolt patterns MIGHT be different.
On my turbo 350/205 there was an adapter between the trans/transfer case. On mine I think it was about 12 bolts (4 on the trans. side, 8 on the transfer case) on later models I believe bolt patterns changed.
I've got a turbo 400 sitting in my shed, wrong adapter and spline count to use with my current transfer case.