Doug's or Hooker (Magnum swap)
keep an eye out for the autozone coupon
I think it brings the coated dougs headers down to the 530 range
I have dougs in my 71 duster (LA motor, with power steering) and they fit fine
the only issue I had was steering linkage interference which was most likely caused by a sagging motor mount
I haven't tried the hookers, but it seems to be "common knowledge" that dougs give you the best ground clearance