Going to use hedman husler p/n 75109 fender well headers . 1 3/4" tubes with 3 inch collectors with this new "Beast" . Same 1 3/4" size tubes were used on the 66 d-dart. I think they should make some serious hp. not too small, not too big , Just right !
upon doing more research on these 1 3/4" fenderwell headers ... I think they will not be a good choice for the 273 .. may take away alot of bottom end power away . I think the sweet spot is 1 5/8".