Steering Box Replacement?!

My steering box started leaking badly after my swap... I was wondering if there is anything I need to watch for when selecting a steering box? My car is a 318 car... I was planing on maybe purchasing a re-manufactured one since i'm on a tight budget... I kind of recall someone telling me that mopars used all sorts of different boxes? Any help is appreciated!

I've called O'reillys and Autozone and while they show it, no one has it...

http://www.oreillyauto.com/site/c/d...=Search_02840_5137327_3183&pt=02840&ppt=C0203