quik Rear end ?

88stangmangt

Active Member
Nov 25, 2003
2,332
1
48
Stafford,VA
I have a chance to pick up a 9" rear for a great price...my 90lx turbo already has a 8.8" swap. for how cheap it is and since my 8.8 needs a diff rebuild. I thought i could build the 9" with a good diff (eaton)moser axles and a nice set of gears and just bolt her up. i am running UCA'S and LCA'S already he says it is 65 1/2 " from drum to drum does this sound like the right size for the mustang? will it bolt right up to my FRP alum D/S and Controll arms??? i forgot to get him to measure how big the drums are to see if they would fit in my 16" ponys.
 
Personally I think the 9" will be too much rear for that car. The 8.8 will be sufficient enough to withstand anything you'll throw at it with a 2.3T. The 9" is heavier, and it takes more power to turn the gears due to the low pinion height. That same pinion height along with the larger ring gear and bigger internals is what gives the 9" it's famous strength. But as with all things, strength comes at a price. It'll cost you in additional weight and loss of power to the rear wheels.

IMO, you should just fix the 8.8. You'll be happier in the end. If you had a nasty V8 that kept breaking 8.8's, yeah, by all means go with the 9".
 
The 8.8 will hold up well into the 10 second range and quicker with the right upgrades.

The 9 in will be heavier, and about the same price to upgrade. Would be capable of being bulletproof though.
 
I'll let you know when I break the 7.5. :D
Seriously, these cars generally don't need huge rear ends. They tend to be lighter with a little less power. In fact, I rarely here of people busting the 7.5, but then again, most people shooting for 11s will swap it out before attempting. An 8.8 will hold you fine. Just get a descent differential in there.
 
Plus, you have to keep in mind that this 9" rear won't have any of your control arm mounting points on it...meaning you'll have to cut them off the 8.8 and weld them onto the new housing, or find some other way to do it. Too much work for what it's worth, honestly.
 
bhuff30 said:
I'll let you know when I break the 7.5. :D
Seriously, these cars generally don't need huge rear ends. They tend to be lighter with a little less power. In fact, I rarely here of people busting the 7.5, but then again, most people shooting for 11s will swap it out before attempting. An 8.8 will hold you fine. Just get a descent differential in there.
actuall the 7.5 that we took out of it was talking all kinds of crap when we got on it...thats why we swaped it out....we were afraid it would make a mess when it went. you can break a 8.8 with a 2.3L T dont be fooled. just thought it would be a good idea for the money. but i do have a eaton diff and moser axles on the list.
 
I forgot to add that my 82 runs high 7's in the eighth on spray and high 12's in the quarter on motor, with a 7.5 in traction lock axle, on drag radials. I have an 8.8 in ready, but the 7.5 seems to be holding up fine. It has surprised even me. I can't see needing a 9 in, or even a lot of upgrades to an 8.8 with a 2.3.
 
ya i have decided to keep the 8.8 i have in. and just upgrade to a detroit locker and some moser axles.......but the motor size doesnt really matter it is the torque that break's stuff. thanks for all the help..........