What Do I Need?

[Bowed]

I have a 79 blazer W/ auto trans that came without a rear drive shaft . When I went to a salvage yard and told them I needed this rear shaft , 33 inches in length and that my yokes were the fixed type at "both" ends , they gave me a drive shaft the right length but it is solid with no slip joint on the shaft . I do not see how I can use a solid shaft with both yokes being fixed . What did they use on these blazers ? What do I need ? Thanks .