We did some tech for Hedman on these particular headers years ago at their request as we were Mopar specific. The headers were tested on 67-72 and 73 newer a-body applications. Without modifications we considered them as a no-fit header at least for the applications we tested. Suggestions were made to Hedman for possible improvements
but it appears no changes were made. Even if the headers were modified above for clearance then it takes a pretty good pipe bender tech to hook them up to clear linkage and everything else. Cutting the 3 bolt flanges off offers a little more room but it still is difficult for an experienced fabricator.