Headers question

I have this 460 in my F250 4x4. I am seeing headers all over the place for a good price, and they are all for 2WD. What is the big differance between headers for 4X4 and 2X4? The only thing that I can think that would effect anything is the transfer case, and that is far enough back from where the headers connect to the exhaust pipe to not cause a problem. The stock manifolds are relativly short, and don't reach very far back into the engine compartment, and all the pics I have seen of 2X4 headers look like they would be the right length. Is anyone out there with an answer as to what the problem would be with hooking up 2X4 headers on my 4X4? Any light you can shged on this subject would help me alot. Thanks guys and gals.

Lary the 460_Fan

http://www.holley.com/HiOctn/ProdLin...HHSCH/4WD.html