Originally Posted by Paul Grant

If you're planning serious off-roading, I would unquestionably go with the conversion. The four bolt flange conversion and a rear prop shaft with u-joints at each end are far more desirable. So you wind up with a u-joint where a rubber coupler once was. You get the inherent strength of the u-joint replacing the softer, more compliant rotoflex. Under use, off-road, it is conceivable that you could tear the rubber coupler. It has happened.

If it's going to be your daily driver with only modest excursions off-road, I would say keep what you have. Replace the rotoflex and forget about it. People like to spend money that they don't have to and over build a truck that was remarkably capable straight from the factory. I'm of the school of thought that would rather keep money on hand for more serious issues, especially if this is your daily driver.