Musclehead17

So I've looked through some other threads about a 7.5 to 8.8 inch rearend in our mustangs, but I picked up a 9 from a friend of mine, I have a 2005 v6 auto. The axle is from the late 80s I believe, it came off a bronco, its in very good shape, spins smooth. I'm looking at a new ford racing diff for it, a drum to disk brake conversion and possibly a flange for the driveshaft, I'm hoping that should be it. If anyone knows of any other forseable problems it would be greatly appreciated!

JimC

How will you mount it to the Mustang 3 link system? Didn't the Bronco use a 4 link?

pascal

You'll need a good welder but have you thought about the rear offset then?

Musclehead17

Just did some research, I'm not able to directly measure my mustangs rearend or the 9 inch, but the bronco was an 84, the internet says those rearends are 65.25 inches, the rearend on mine is 65.5 inches. What impact would .25 inches have? and this is before a drum to disc conversion, I have no idea what that would do. And I'm still researching into the 3 or 4 link suspensions. My friend also has an 8.8, he's offered that also if this 9 won't work. May look at that if things get hairy with this 9 inch

pascal

On the 9", you'll have to make and weld every bracket needed to hang your shocks, LCAs, panhard bar, spring saddles, sway bar and top perch.
All this crap has to be a precis fit as well, lots of mock up to do...
Unless you plan to make close to 1000hp, the 8.8 will be fine.

AMWill

As cool as the Ford 9" is, I would switch to the 8.8 if you have the chance. You're looking at a pretty big custom project if you want the 9" to work smoothly. The 8.8 is a much more direct swap and as you already mentioned, there's a ton of write-ups for it. Stick with the 8.8 if you wanna save yourself from a lot of headaches, IMO!

I still wish you the best of luck though!

Shane

Nice Pony

The For 9" is also know to rob horsepower so unless you have horsepower to spare the 8.8 would be much better and as long as it is out of an S197 Mustang will bolt right in with the pinion flange being about the only thing that may need to be changed.

ffstorke54

I have put a 9 in rear in a s197 before and its not worth it, we changed to a triangulated 4 link and removed the fuel tank if your not running a crazy engine it will take away more power then its worth, and it will need to be cut shorter to fit under without your tires sticking out of the wells. There is a 9in direct bolt in rear for the s197 avaible for about $1000 its the cobra jet rear

spaseghost

Wouldn't the 8.8 be a pretty direct swap?

Musclehead17

Alright guys thanks for responding, I've been preocuppied the past few weeks as I almost lost my transmission, the torque convertor went and almost took a few of the gears with it. I picked up the 9 from a friend who didn't need it, figured I'd take a peek into if it's ever been done or not in a s197. My friend also has an 8.8, but it's from the 80s I believe as well, but he's offered to trade the 9 I have with the 8.8. May look into that then, but I'm still dealing with this poorly built transmission, so it'll be a while before I can focus on this again