New Guy

Hi Guys, I am new to 4x4 World and need some help. I was driving home tonight and stop to help pull a guy out of a ditch, (I live in Oklahoma and we just got hammered by a Blizzard.) I was already in 4H, and shifted to 4L with no problems and proceeded to pull him out with no problems. However when I shifted back into 4H, to go home, I noticed the truck was making a light clunking sound under my feet, I shifted back into 4L and the sound was very noticeable and I could feel in the shifter while driving. I put pack back into 4H and proceeded to limb it home (still making the noise, not as loud, can not feel it in the shifter). Once I got home, I played with it out in the driveway and it still there. I checked the U-joints, and they don’t have any slop, and when I put the Track and Transfer case into Neutral and spun the front driveshaft shaft I head some noise in the Transfer Case, is this normal (not clunking)? I am 90% certain that I need a new Transfer case, unless you guys think otherwise. Please Note: The truck runs normal in 2H and the 4 wheel drive still works, its just makes the clunking sound. I have located some used Transfer Cases online in the 300-400$ and have question about compatibility. Can 5 speed Transfer Case be a direct swap for 4 speed. Does it matter if came out of a Bronco or F250? Is there anything else I should be looking for? Would I be better off pulling it and having it rebuilt? Does anyone know how much it cost to have one rebuilt, if I pull it (I thank its a BW1356, will pull numbers tomorrow.)

Thanks