The Jeep guys have been doing this for a long time now. It is called Hack and Tap. YJ's and TJ's have long output shafts and short driveshafts. They hack the end off of the output shaft, drill it out, tap it, and attach a new flange to it. You have to get a new driveshaft with a slip yoke.
I have seen this done and it works very well.
Cwkick