Lazor05

So i'm looking at changing my 7.5 rear end out for an 8.8. I was wondering if anyone had a write up on this? I looked and couldn't find anything on a mustang around my year. I have an 82 gt, so what year should i look for to get the 8.8 out of? will it just bolt in? and what about the brakes, I have drum and im pretty sure the 8.8's have disc. Please be as specific as possible because im new at this stuff. Thanks

uedlose

it should bolt right in the brake hose mount might be diff. 86-93 V8 cars is the rear you will be looking for maybe even 85 I cant remember. and those years have drum brakes also. other then that its just remove some bolts and reinstall them. control arm bolts will be tight. good luck and have fun

mustangman02232

you can throw a detroit true trac or Eaton LSD and the 7.5 will be stronger then a stock 8.8 for roughly the same money

uedlose

the carrier may be stronger but it will still be weaker due to the gear size 7.5 vs 8.8. 7.5 is very light built compared to the 8.8 you can only put so much metal in the small center of the 7.5. in this case bigger is better.

projectresto83

A 8.8 rear will bolt right into your car. 87-93 mustang 8.8 rears are drum brakes just like your 7.5 rear. The brake line for the rear is the only thing that will take a few mins of work. You will have to move the brake line on your car (or extend it) to the center of the car to allow it to connect to the brake line on the rear. If you are wondering the brake line was moved to the center to allow room for tail pipes .

Lazor05

Alright sweet. Thanks for the help guys. I guess its out to the junkyard. And do you know what gears came in those?

Modular_Madness96

2.73-3.08 are the most common and the garden variety 8.8 gear ratios.

Marc S

If you find a turbo coupe most of them had 8.8 diffs with either 3.55 or 3.73 gears. I have one with disc brakes in the 85GT that I bought new. They are about 1/2" wider per side but bolt right in also. Mine has been in there since about 1989 I believe, but has held up fine to 347 5spd combo. Ya I know, I'm old. It is an easy swap, not to worry about being new, I was new once. You can do it, just make sure the car is supported on jack stands before you start the project though.

mustangman02232

i very rarely ever hear of a R&P breaking in a 7.5, there are a few newer 6ers with 400+ HP running a 7.5 with no problems, the carrier is the weakest part... as ive blown 2 of them up

Marc S

I agree with mustangman, the 7.5 is tough. My 85GT had a probably 200-300 passes at the dragstrip and had more street racing runs on it than I care to remember. back then, the car was an auto, had 3.73 gears and a 3000 stall converter in it and a 200 shot of nitrous. in about 1992 I put a 429 in it and it ran 11.80's and still had the 7.5. The car sat in my shop from 2000 until last year when I put the 347 5spd in it so I decide to retire the 7.5 but is was still going strong.