I have owned and maintained trucks for over 50 years. The purpose of a two piece drive shaft is to absorb more torque. That is why the 4 speed had a 2 piece with a center bearing. If you are not going to be starting off with heavy loads, a one piece drive shaft will work. If you plan on untracking heavy loads, stay with a 2 piece drive shaft. One piece drive shafts are also more vulnerable to vibrations.
