Hey Neal, are you speaking from experience?

 

My 1988 F150 has an aluminum drive shaft. It was news to me back then. It had to be replaced under warranty as the clunking sound I thought was a universal turned out to be the drive shaft. 160,000+ with no other drive shaft problems. No towing and only light hauling.

 

Do we know why some are aluminum and some aren't? Does anyone have an SC long bed, with a steel ds?