racerlall, therocks, NANKET & Cab_Burge Thanks for the helpful hints!!!
Here's an update: The car shows signs of being a former service vehicle. Those signs are it having a radio 10 code cheat sheet on the driver's side sun visor, a coaxial cable under the headliner that lead to the trunk and signs of it being a fleet car via rubber flooring, no radio, no A/C, white in color etc.
The car is an automatic. Just confirmed it is a Sure Grip by doing the wheel spin test. The lug studs are 7/16 and not 1/2 (strange). And the gear ratio tag reads 2.94 (nailed it NANKET).
So WOW a /6 car with sure grip rear end, didn't see that coming.
So in case I need to add gear oil, the Ford brand is what I should use? Is it two part or all in one bottle?
I'm thinking I'll be fine but I want to have a back-up plan in case fluid needs added.
Thanks again guys.