904 to 727 swap

I want to swap my 904 for a 727 in my 340 73 Dart Sport. Is the main body of the trans the same? In other words will my cross member line up? Will the longer angle of the bell housing fit inside my tunnel? Is the kick down linkage the same, Not too worried about the shifter linkage since I already have a B&M cable shifter. I know I will need to have the correct tailshaft, Yoke, flex plate and ujoint. Just want ot make sure I'm not biting off more than I can chew. Any advice will be appreciated.