Headers for 73 Duster with 451

The Hedman’s will not fit with a 440 using Schumacher kit with 68-72 k-member. This was on my 68 dart with auto trans. I was able to get the passenger side on with minimal torsion bar interference but drivers side was a no go. This was with manual steering and the steering shaft collar shortened to fire wall. The torsion bars were also 6 cylinder bars. Hope this helps