I have a '99 explorer xlt with a 4.10 limited slip differental and was wanting to know if i could replace it with a 3.27 differential that isnt limited slip. The tag on the 4.10 says S615E and the tag off the one i want to switch it with says S610E.

 

I don't know for sure if that can be easily done, but let's keep one thing in mind.

If you go to a 3.27 ratio you will gain increased torque at the wheels , but lose economy.
There is always a trade off, lower ratio , better mileage less torque, higher ratio, more torque lower mileage. The difference may not be any concern to you , just thought I would mention it.