I thought there was one brand of headers that would fit, hopefully someone else will know which ones. If it were mine and no headers did fit I would buy a set and have the one pipe on each side modded as necesary (run it out the front and down through that triangle hole in the K-member on each side).
I just did the opposite on my Challenger, I welded up a "Mickey Mouse" mount for the drivers side and welded up a bracket to use a wedge isolator on the psgr side on the stock wedge K-member with a Hemi block. My Hooker 5210's fit like a glove (after spending a weekend fixing the port alignment).

Sheldon