(There is a discussion on driveshaft shortening and 1pc vs. 2 pc shafts from July 4 2015 that may be of interest to you. The Post is titled 62 Cutlass Flywheel Lightening but it moves into driveshaft shortening and two different methods.)
Currently we are going to keep the 2 pc shaft at this point. We have set the angle of the eng/transmission to form a straight line from trans tail shaft to the Center support bearing as recommended by the driveshaft shop and as the original is set up. This is typical of 2-piece shafts with a ujt at one end of the front shaft. No offset of angles is desired for the front shaft since it only has a ujoint at one end. Note that the Roto 5 has a fixed UJt yoke at the rear of the trans while the 200C or 200R4 has a splined shaft for the rear UJt which moves on the trans output shaft. We are leaving the rear shaft alone. We will be setting this up in the next couple of weeks so I’ll report on results.