69 Dart GTS 340 to 440 project

I have a small budget And a few necessary parts, engine tranny and high performance exhaust manifolds from a 70 440 road runner. I would like to know the procedure that needs to be done to the 1970 hp manifolds to make them work in a 69 dart gts body such as milling and where to mill at and how much to mill. the car has manual steering and manual brakes. it has a 727 tranny. And any information pertaining to put in a Rb in A body any information would be appreciated. I'm going to use schumacher Motor mounts.