Header fail, stock manifold time!

Ok going to need a back story here? What car, motor trans and headers are you dealing with?
1967 dart 318/904. Bought the headers on summit for $150. Just can’t get them to fit. Spent a day tried everything I could think of. Jacked up the motor, moved the motor to the side with a big bar, pulled all kinds of stuff off the motor trying to make it fit. I think they are just too big. One guy said the only way he got them in is pulling the motor