74 to 70 Dart parts swap

No. The slant 6 transmission while a 904 is entirely different than a v8 904. That said, the driveshaft from the 74 will fit just fine.

Are the universals on the drive shaft to the rear end the same? I need to put the rear from the 73 (I ended up with a 73 not the 74) into the 70 with the 6 cylinder drive train and still have it drive? I just need to be able to move it in and out of the drive way until I get the donor car out of the garage.