Is it a 9"? I'm wanting to upgrade to a 9", and a local jy has a '72 galaxie... the car is sitting on the ground, with no wheels on it, so I want to find out if it's a 9" before I go through the hassle of lifting up the car.

 

Bottom nuts holding the case on. If a socket fits on all of them, it's an 8". If you need a wrench to remove the bottom nuts, it's a 9". You'll need to lift the car anyway to find out. There should be a tag on one of the case bolts saying what size it is and what gears are in it.

Before you go grabbing the diff, will it be the correct width? How do you plan on putting it under a third gen? A third gen uses torque arm suspension. Are you going to replace the axles with aftermarket ones with a chev bolt pattern or will you use the Ford brakes, bolt pattern and some ford bolt pattern rims? Chev rims won't fit on a ford.

 

It will probably be too wide, if it is i will narrow it, converting it to use 3-link is easy as long as you can weld, yes i will use ford brakes, and I already have dual bolt pattern wheels on my car.

I have google'd my original q and couldn't find an answer, so I still need to know...

 

Ford started using the 8.8 rear end in the Galaxy and LTD in the mid 70s, so it could be one of those. If it has a bolt on cover on the back then it is the 8.8. If not then it should be a 9 or 9 3/8. If it is a 9 3/8 you won't want it.

 

72 should still be a 9" with 31 spline axles.

 

Well, that answer sounds sure enough to make me go and check it out.