can my 1999 Altima have a 2003 engine?

I brought a 1999 Altima in 2000 and had to have a ball joint replacement about three weeks ago, had trouble fixing it. I was later told that the reason was the car has a 2003 engine, A 1997 axle. Okay I can see the axle but is the engine possible if the car has never been wrecked