Vibration problem!

[cpumatt]

Hey guys, lately I've been driving down the road, and around 40-50 mph, when I give it gas the whole truck vibrates like mad! On the highway it's smooth as butter, in slow speeds it's fine.

Could this be to my old tires? My ujoints I need to replace? I'm stuck! Anything helps.

 

[MDmounty]

I had a problem like this one time turns out I needed a new u joint on the back of my driveshaft going into the rear axle