how to tell which options did a car im looking at come with

[Lightning 06]

ok, Im looking at a '90 GT to replace my poor tired '89 4 cyl. from what i've seen the car's got the HO version of the motor, busted A/C (the guy has the parts for it, but im gonna pull the A/C out of it anyway, it's too much weight) and a 5-speed. the option im looking for is to see if it's got the Trac-Lock rear end. how do you tell without pulling the Diff cover off?

 

[ECU5.0]

all the mustang came with it. youre good to go. it might not work, but tis back there. jack the car up and spin the wheel...if both turn at the same speed its all good