Lost All Torque..

[robbd]

Hey, Im new to the forum but I could REALLY use the help!..

I recently moved, and before I did, I Gave my truck (1999 GMC Sierra 1500 4x4 5.3litre) a little tune up (New Plugs, Wires, Transmission Filter, Fluid, Oil Change, Fuel Pump, Fuel Filter) When I removed the plugs that were in there, they were set to .0040, when spec on the truck says set to .0060. I set the new ones to that and after doing this tune up my truck went from running amazing to running like ****. I thought maybe it had something to do with the Spark plug gap so i pulled them out and swapped them back to .0040. Im still having problems. Whenever I step on the gas hard it revs to about 1800 rpm and just slowly gets going until top end when it seems to pull a little better. Before the tune up i had Alot of power behind the pedal, being able to drop a gear to 4000 rpm but now i can barely pass someone on the highway. Seems like I just have no torque at all. Any Idea's ? Any Help Please and thanks!

[Draenor]

You may of had some trash dislodge in the fuel tank. Can you make a decent run at part throttle? If it runs better, I would change out the fuel filter again.