Which v8 do I have

Howdy guys, not new here just new to Silverado trucks.
I just picked up an 05 Silverado 2wd regular cab stepside with auto, and I can't figure out which v8 is under the hood. If I'm correct it is either the 4.8 or 5.3 because the 6.0 would be badged.
So how can I tell which one I got?

Thanks in advance.

Look at the window sticker if you have it or the sticker that's on the shield above the radiator. Let us know what you have. Most trucks that I have seen that is like yours most likely i would say you have a 4.8L

4.8 it is.
I don't have the window sticker so I took a look at the sticker above the radiator, nothing, but it was written on top of the airbox, so there you go.
Thanks 97sle I appreciate the help.

My window sticker said standard equipt. 4.8 litre engine, I was pissed I went back to dealer, and said we had this disscusion about I wanted the highest performance 5.3 available. I do have the 5.3 reguardless of what the window sticker said.I read down further in the options listing and it says vortec 5.3 L, 310 HP, aluminum blk v8