Headers won’t fit in 67 440 dart

Silly question- but do you have the tail end of the engine/ trans up high enough? It looks like your tail end is sitting quite low which is also throwing off your geometry.
Also is the engine too far forward? Mounts not on correctly will put the engine forward.
Measure the trans cross member center bolt (rubber lower mount bolt) to a k frame bolt hole Center line on the car (with the cross member and rubber mount installed. Then measure the same on the k frame to trans rubber mounted to the actual transmission. It should be with in 1/4” of an inch in length.