No, all manual rear diffs in the US are 3.545. You can double check this by looking at the label on the rear diff cover. If it says 3.545 and you have the matching t-case with the trans, you're golden!
The t-case I'm selling is completely rebuilt. It looks like it's brand new. I'm sure if you look around enough you could probably find a good used one for around $100. Mine is on the shelf, ready to go and has a 14 month, unlimited mileage warranty though