Newbie, need help with rear diff fluid change.

Hi guys, new to the grand marquis crown vic scene. I am trying to get some info on what type of gear oil i will need to change the rear diff fluid. I have a 97 grand marquis ls with the handling package n 3.27 rear end. Is there a gasket available for the diff cover or just use rtv?

I can't remember the weight of oil sorry. But yes Autozone and O'Rielley do carry a reusable gasket. Also if you have the handling package you probably have the limited slip differential so you will need a friction modifier as well.