Can I swap the front end of my car?
In a word, yes!
Under all that sheet metal, lights, bumper, etc, the basic shape of the car (the metal frame rails, etc) is the same between a Cavalier and a Sunfire. Even first and second generation J-cars are the same underneath everything.
In essence, you can swap whatever front end you want, within a generation. There have been many, many people who have swapped from a Cavalier to Sunfire front end (or vice-versa). All you really need to do, is take off everything right down to the frame, and swap on the new parts.
There are many parts that remained the same over several years. For example, the hood from a 2002 Cavalier is the same as the hood on a 1995 Cavalier. Same goes for a 2002 Sunfire and a 1995 Sunfire.
Some parts may look the same, but have slightly different construction between years. An example of this would be the fenders on a Cavalier. They look the same from 95 right through 2005, but the brackets for the corner light are different from 95-99, from 00-02, and again from 03-05. In most cases, you can swap any parts that are different, but be prepared to deal with such minor details.
Likely the most difficult part of a front-end swap will be the wiring. Depending on what year car you are going to and from, will affect how much rewiring is necessary. If you stick with single-bulb headlights, you will have less re-wiring to do than those swapping to twin-bulb headlightss (or vice-versa).
dazink has written an extensive FAQ to do with front end swaps. Please refer to it for more information:
http://www.j-body.org/forums/read.php?f=7&i=227562&t=227562
