Will an '02 rear diff fit? or did they change them in '03?

 

Any stock rear diff from a D2 (assuming it is in good repair) should work in your '03.

If you're looking to be a cheap as possible, then in addition to the links provided earlier, I'd recommend calling some of the following parts guys to see what they have:

Will Tillery (#1 Community For Land Rover Owners - The Rova Guy)
PT Schram (260-804-0458)
Randy Williams (Rover Bones Home
or Marty Powell ('Drillbit' on D-web, or 'iamthedrillbit' on eBay)

 

Excellent. Found one on eBay for 150 + 80 bucks shipping. Only 97k km on it. It is from an '02. Comes with a six month warranty. Think I can beat that anywhere else? There were others for 80 bucks, but didn't seem as in as good of shape, and didn't have a warranty.

 

If you can find one locally, then you'll save the shipping which is a big chuck of change. Have you hit up CL or for eBay sellers within a short drive away?

 

I live in a low population rural area. The shipping kinda sucks, but I couldn't find anything other than eBay, or somewhere like randysringandpinion.com.