74 Dart Sport. Hedman Header Hell.

That's your torsion bar, part of your suspension. You need to remove the engine mount bolt, then place a piece of wood between your oil pan and jack to carefully lift the engine up while the car rests elevated on the stands. Once you raise the engine a few inches, they will fit easily. You may need to remove items like your radiator shroud to prevent the engine from getting jammed while jacking it.