I will be going to look at a 9" rear tomorrow and just need some tips on how to tell if its really a 9". Is there any way to tell, just by looks??
-thanks.

 

The carrier section is bolted to the housing, just like the 8" rear, only with a 9", you can't use a socket on the bottom nuts, you have to use a wrench to remove them. (The casting won't let you get a socket on them). Sounds confusing, but when you see it, it will hit you...

 

The housing should be 52.25" wide from flange to flange for your model and axle face to axle face is 57.25". Rounded backside

If it is a 67-70 then its 54.25" and 59.25". "Hump" backside with 2 dimples

 

John721 has got it right. Those bottom bolts are a real pain.