James Johnson

I have two mustang one a 1991 lx the other 1996 gt. What I'd like to know is ;
1)Can a rear end from a 1991 Fox body fit under a 1996 gt?
to make a long story short, my plans for the build have changed for the 91. When I started on the 91, I replaced shocks, springs, control arms and gears. None of this I'll be needing know because I'm building the 91 to race.
The 96 I'm putting a coyote in and I want to update the suspension. So can I put the 91 rear end under the 96 stang.
Any help would be greatly appreciated.

Buck Sergeant

James, hope this helps you out. Most factory Solid Axle (Live Axle) Mustangs from 1979-2004 are equipped with the standard 28 spline axles whether it be 4 lug or 5 lug. 2005-2014 Mustangs are equipped with 31 spline axles which are about 30% stronger than the factory 28 spline axles making them a popular aftermarket upgrade for 1979-2004 Mustang owners. Swapping over to 31 SPLINE axles will require the use of a 31 SPLINE differential to function properly. These are great axles if you plan on taking your Stang to the next Level!

FOX LENGTH AXLES VS. SN95 LENGTH AXLES
79-93 Mustangs - 29 3/16" long rear axle.
94-98 Mustangs - 29 31/32" long rear axle.
99-04 Mustangs - 30 11/16" long rear axle.

Derf00

You will have to take a look at the mounting points of the Axle between the two cars. A lot of the guts like the pinion gears, seals, and bearings can go back all the way to 1979 but the complete axle with pumpkin (the shell) may not be interchangeable. The control arms are the biggest difference between them. Fox bodies are quad lower control arms vs the SN95+ are single arm on each side. I'm not familiar with the upper control arm differences between fox bodies and SN95+ models.

Buck Sergeant

James, as far as I know, the 8.8 rear ends are mounted the same from 1979 to 2004. If you are putting a coyote in that 96, I would strongly recommend installing lower control arm brackets with a "cross tube" tying them in. Of course, all rear end components must be updated to 31 spline specifications, and adjustable. Don't forget your c-clip eliminators.

Buck Sergeant

James, I may have given you some misinformation. Here is the new news. The rear end is the same from 94-04. The 99-04 rear ends are about 1.5" longer so you'll have a more flush look on your wheels, but it still has the same bolt set up. You shouldn't need anything other than the rear end assembly, pretty straight forward swap. BUT, I forget you are going from 91 to 96. This new information makes it doubtful the 91 is a bolt-in with the 96.

88Mach1

The 91 rear will fit just fine as long as you swap the 96 axles and brakes onto it.

Buck Sergeant

88Mach1, thanks for the clarification. It's good to know someone will catch my back. Again, thanks.

wbrockstar

I believe the 94-98 axles are 3/4" longer than the Foxbody axles plus they're 5 lug vs the Foxbody 4 lug.This is one reason why you must swap axles if using a Foxbody 8.8 in a SN95 since Foxbody axles are 3/4" narrower than SN95's.

Buck Sergeant

wbrockstar,88Mach1 and Derf00, you are right on the money. The first thing I did after dropping my 331 stroker in the 1987 foxbody was to install,in the 8.8 rear; 31 spline high grade, five lug, axles, new trac-lok 31 spline carrier, with carbon fiber discs, C-clip eliminators, and replaced ALL rear suspension items with STEEDA adjustable replacement items. Also,just to be safe, a 3 quart ford performance differential cover with 75-140 ford synthetic oil and 4 oz of friction modifier. I went a little crazy on the rear because I am installing a 200 hit of juice. Everyone's information is going into my log book.