7.5 or 8.8
 

I have a 90 Gt and was gonna order some 3:73's but need to know what rear end I have a 7.5 or a 8.8 do I have to count the nuts on the pumpkin or what, and i'm ordering the gears out of my mustangs unlimted catalog so whats a better deal the kit by ford motorsports which is like $250 and comes with redline gear oil, cone roller bearing, bearing race and shim kit or just the gears for $189 same company?

You've got 8.8 rear!

sorry for keepin this goin but where did u find the 3.73's for $150 I cant find them anywhere for that price?

Prices
 

The prices vary for the gearset,they average between 150 and 189 depending on the name on the ad,if your 8.8 has a few miles on it you will be able to tell in a safe area dump the clutch to check if both wheels are spinning,make sure the car is pointed straight also.

There are a lot of differentials out there that can replace it,if need be,so look around,there is MW,Drivetrain Direct,Drivetrain Specialties,lot of places.

Good luck and keep it shiney side up