2000 Silverado 1500 - ExtCab Z71 - INJECTOR HELP

SOOO, I have owned this truck since 2007... It now has 350k miles on it and was running perfect until my fuel lines rotted out... Just put new ones on, and i'm guessing the fuel system sucked up dirt in the process, because now I have a mis on #8... Using my scanner i checked, and when i turn off the injector, my miss stays. I pulled the injector and sure enough, its clogged up like CRAZY... I tried to clean it, but had no luck..
So I'm just going to replace it... Here's my problem...
This truck should be a 5.3l stock... I never swapped the engine or fuel parts / cam.. NOTHING...
Here is the # on the injector that i pulled out: 25320288
This comes up as a 2000 Silverado 6.0l injector.
As far as i know, in 2000 the 6.0l was not offered in the 1500.
I don't think the engine was swapped, as everything looks completely stock and all the parts are still OEM (the ones i haven't replaced)...
CAN SOMEONE PLEASE HELP ME FIGURE THIS OUT?!?!?! Before the last few hairs I have on my head migrate to my back with the rest of them? lol