What is the purpose of a 2-piece driveshaft on a SWB?

[71-C10]

What is the purpose of a 2 piece drive shaft on a SWB? Looks like the center bearing would be a weak link. My 71 SWB has a 2-piece, and my 68 SWB has a 1-piece.

Eddie

[lilred67]

your tranny doesn't have a slip yoke on the tailshaft, therefore you need the 2 piece for the slip yoke behind the carrier bearing.

[R.L.]

Somebody said somewhere on this site a few months ago that it dampened vibration at speed, my younger brother had a 80 model swb he couldn't keep a u-joint in and after a time he went to a junk yard and took a Chevy one piece drive shaft off a 50's model and did away with the two piece stuff. He drove the truck several years after that. 55 was the speed limit then he didn't complain about vibration to me.

[ubtripn]

I heard if a one piece gets too long it becomes too hard to balance it or at least it can develop issues due to size, mass or weight that keep it from operating smoothly.