i looked through the search engine but nothing came up pertaining to my problem. my vibration only occurs when i take off kinda hard. well harder than i normally would while casually driving.

my rear end is starting to sag die to my engine being in the bed of the truck for four months. unfortunatelly for now, my truck does have lift blocks at the moment but i plan on gettin rid of those very soon!

 

Worn engine mounts or driveshaft U/Js?

 

sagging springs and blocks= axle wrap under acceleration. could be amplifying worn rear u-joint issues or actually letting the axle rotate and bind the u-joint.