Headers for a A body
can confirm on the challenges of headers in an early narrow body. anything but tti/dougs full length and you'll need to be sharp in the tubing and fab department. when i built the headers for my dart i dumped the collector down the back by the firewall. while better than the mid-block location of shorties, that presented a whole 'nother list of problems what with the 4spd and all.
anything 67 and up is a breeze comparatively speaking, and in some applications even the lo-buck summit headers aren't too awful of an install.