2003 shudder

I have an 03 dblcb 4x4 that when accelerating as soon as I hit 80km per hour the truck shudders for a few seconds than returns to normal.
Am thinking driveshaft possibly but am wondering if anyone else has experienced this. This in not a front end vibration at all. The entire truck shudders. Truck is lifted. It did this before the lift was put in
Any input is appreciated

 

I think you're right about the driveshaft.

 

Its pissing rain the last few days so I having ventured under to have look. Just wondering if the driveshaft is warped can it be fixed or does it need to be replaced?

 

Update on this. Not the driveshaft. It was misfiring due to the plug wires and plugs. Changed it all and good to go. I never would have thought misfire but I thought I would take it into a shop and they suggested hooking it up to a diagnostic machine and they solved it right away