Ive got a 9'' rear from a 73 cougar planning on using it in my car. problem is I don't have access to a stock rear from an f-body. How wide is the stock rear and what is the narrowest rear you can fit under an f-body without tubing it or using some crazy offset rims? The rear I have is 61.25 inches from hub to hub. I got it for free so I'm hoping it will fit with little modifications such as welding brackets. And changing over to a Chevy bolt pattern.

 

The 3rd Gen rear is about 61.75" wide, and fits under the 4th Gen. Whether you need to "tub" it depends on the backspace and width of the wheels. The 4th Gen rear is 64.75 wheel hub face to wheel hub face.

The torque arm bracket is going to be a challenge. Here's the Moser solution - 3 tubes welded to the housing for bolts, and a huge casting that bolts to the 3 tubes. Hard to sort out the TA from the casting, but you get the idea:

 

id love to have the nine for when im launching on a 150 shot off the transbrake but im sacraficing my c6 vette wheels because of the offset. is it just as easy to lengthen a rear as it is to shorten it? I know i will need new tubes and axels but they are readily available. that way i can have a set of prostar/ mickeys for the week end and c6's for the street.

 

grand torino at 65 and 1/4 outside of axle flange to axle flange
the funny thing is it looks like it will bolt in

there are plenty of fords that are longer. trade and get a longer one to shorten