i work with a guy whos truck is a 2002 5.3 with a drive by wire wtf lol he had a service engine light on and code 1518 throttle sensor, so i looked under the hood to make sure he had a good connection and holy **** drive by wire lol i steped back and looked at the front end and it was the same body style as mine lol

 

I just found out that even some of the early NBS trucks were drive by wire also. Bryan from PCMforLess informed me of that when asked which mine was. I originally thought that the switch over was 03, but I guess not. Kinda like how some 99's and up have AIR, and some don't (mine doesn't). Also, I think some 02's have EGR while others don't. Read a thread where someone mentioned that the 02 didn't have EGR, but when I went to the ACDelco website they had a part number for it.
I guess it depends which plant the vehicle was assembled at, and if it is Federal or Cal spec, I suppose.