when I let my fuel tank get below 1/8 tank my engine spudders at start under normal accelaration.I fill it up with gas it runs fine until 1/8 tank.where is fuel filter on this truck?in gas tank mabey.

This has a combination regulator and filter which is on top of the pump module that goes into the tank. Most likely your gauge is not reading accurately and you have less than 1/8 tank.