From about 1000 rpm’s to 2500 rpm’s it sounds like marbles in a can. It’s like coming from under the drivers side ish. I can’t figure it out. Does anyone have an idea?

 

How many miles are on your truck? It's a 2005?
When you say, "1,000 to 2,500 rpm's", is this stationary or while moving?
Rattling is the description many use for broken timing tensioner guides.
The tensioners themselves are recommended to be changed at 100k miles by knowledgeable folk here.
When you hear the rattling, the damage is done.
The driver's side (left side) timing parts can be changed with the engine in the vehicle.
Repairing the passenger's side requires engine removal.