drive line swap?

I've got a 1965 dodge dart 2 door with a slant 6 and a 904 auto tranny.I'm up grading to a mid 70s 904 automatic.I got a drive shaft out of a 67 dodge dart 2 door with slant 6.the yoke slides right in but the shaft is too short!Is there a fatory drive shaft that will bolt right up or if not what are the measurements from eye to eye so I can take the yoke and end piece to the drive the drive-line shop?