i have a 2003 limited slip rear axle that i want to replace my '97 axle with. is there any differences between these?

 

If they are both the same diff, 8.8 or 9.75 then you can swap them. The 8.8 came with the 4.2 and the 4.6. The 9.75 came with the 5.4. I would not swap a 9.75 for an 8.8 but the other way would be fine. If you do swap different sizes, then you will have to change drive shafts probably.