I used hedman part #88300, in my Comet. These hedders are for a 289-302/C$ in a 64-73 mustang. However, the collectors would not clear the extra width of the AOD, so there was some modification needed.
Here is a picture of the mods I had to do to them. I cut the collector off just past the tubes, and re-welded them back on angled off to the outside of the car. However, this caused problems with a shifter linkage and it took some thinkin to fab one that worked.
<img src='http://img.villagephotos.com/p/2005-1/929046/headercloseup.JPG' width=864 height=648 >
Here is a picture of them installed after the mods.
<img src='http://img.villagephotos.com/p/2005-1/929046/underside-headers.JPG' width=639 height=480 >
But in the end, they ended up working fairly well, and they don't hang too low.