10 Day Magnum Swap - '65 Dart 270

OK couple more questions. Are you using headers I'm guessing? If so what kind and do you usually have to jack motor up to fit them or can motor be bolted in and slide them in after. I am wanting to know for my 74. The factory magnum manifolds would not fit so I had to order headers. Wasn't sure if they will go in with motor bolted completely in or not.