Guys may be a dumb ? but keep in mind that I am an idiot as far as working on cars. Have heard stories about the rear end breaking in our camaros and everyone talks about if it does they will get a Ford 9" rear end. ? is it as simple as finding a wrecked mustang and buying the rear end and making the switch?

 

its not quite that simple. first, production mustangs built since the beginning of the fox body (1979) were built with the 8.8" rear, not the 9". people do swap 8.8s into f-bodies but its not a direct bolt in. the mounting points and suspension setup are totally different. plus you need a custom driveshaft and such to fit.

its true that the stock f-body 10-bolt rears are a little fragile but they probably won't break if you don't launch em on sticky tires too much. there ARE guys going 10s on stock 10-bolts...they won't last forever but they aren't toothpicks either (though i did break one already.)

your best bet is to buy a converted f-body specific rear axle from a reputable company (moser etc.) you could always go with a GM 12-bolt as it really only tolerates about 4% less hp/tq then the ford 9 inch. 12 bolts are usually sufficient for most upgraded f-bodies. if u really want the 9 inch, they make f-body specific rear axles for those too. shop around.

 

Thinks for the info, it cleared everything up.

 

How much hp are you making? Do you go to the track much? Are you still running a stock gear? I would not worry about your rearend until you start making some good hp and start running sticky tires.

 

id probably agree. like i said, the 10-bolt is a little fragile but it isnt worth it to just junk it right off the bat on a stock car. is ur car an M6 or A4???? if its an A4, dont bother with the rear. launching an automatic preloads the rear and puts a lot less stress on it then popping the clutch at 6000 in a 3400 pound car.

im still running a 10-bolt in my car, and it 60 foots pretty hard so u may not need to worry about a rear right now.

what exactly is ur setup? tranny? modifications? tires?

 

I am running a stock gear now after my 4:10 was shredded all to pieces. MT slicks, 175 shot of nitrous, 4:10. and bunch of bolt ons does not make for a good combination. Have to admit though it held up for almost a year before rear end gear expolded

 

yea 175 shot + slicks = 12 bolt....

 

If you are planning to spray the car and run a sticky tire than it is time to upgrade to a better rearend. I am assuming by stock you are running a 3.42 gear? The funny thing is that I have seen stock rearends take tons of abuse. Typically, people start encountering problems when they change out the rearend gears and go with a 3.73 or 4.10. But I still would not upgrade until you break the rearend. The reason the 6 speed is more violent than the auto is because you are basically shocking the driveline rather than preloading it with an auto.

 

Good explanation. Yeah, the rearend held up really well with the 4:10s for about a year. I even drove it for a cpl of months before I realized the gears were messed up. Heard some noises one day, took the gears out and nearly all the teeth were gone.