The earlier trucks, 73, 74ish, came with a transfer case "L" bracket, but newer trucks are just like what you have there, as do I. One crossmember, under the back of the transmission, nothing holding the transfer case besides the bolts. Nice, huh?
As for the crossmember drop, that is what I have on my truck as well. Just 4 aluminum blocks. Skyjacker is who I got mine from.