'72 Big Block k20 Headers - Need better fitting headers

[nitrosport_5]

Hey guys, Just getting my truck tore down to replace the cab and looking at the headers, I dont know if they are the correct size for the engine/truck, or if they were just a random set of headers shoe-horned in there. Also, I was told by the previous owner that the engine was moved an inch back, or forward, or upside down... i dont remember . Is this somthing that would have been done to put a big block in a 4x4? I should have gotten pictures of how far the engine is from the firewall but didnt think of that until i was back at home.

Here are the pictures of the header fit. The engine is a 396 and someome has carved the frame to fit the headers. Not sure what headers they are, but is there any other headers that may fit better? Thanks in advance.