Truck will move but feels like it's dragging a house. Goes through gears just doesn't feel like it has power. In park the truck will rev to the limit, but doesn't wanna seem too while in drive

 

Gas or diesel? What year? Auto or manual?

 

Kinda sounds like a clogged cat to me. Had a very similar issues a few years ago with my 96 and turned out the catalytic converter was done. Some pieces inside had broken apart and shifted around just right to plug it.

 

If you have a 318, then that is totally normal.

Good little engine, just waaaaaaaay too small for a truck.

Then add in deathflash and well. . .