How many splines is the input shaft... the front shaft? Is it 10 spline 1 1/8 diameter. Do you still have a torque tube?

As far as I know that transmission will bolt up to your bellhousing and use your stock clutch. That being said, there are versions of this transmission that have different splines on the front. If you have a torque tube, and a closed driveline, now would be the time to convert to something else. The saginaw is a side shifting transmission. You could get a "hurstlike" shifter and shift it from the floor. You may have to cut a new hole in the floor for the new shift linkage.
The best way to tell for sure if this is going to work, is to compare the fronts of the two transmissions. You may have to change out the front bearing retainer to fit your stock throwout bearing.