8 1/4 questions

[Tang72]

Alright... time to get some dumb questions out of the way.... My 72 charger is still sitting on the 8 1/4 open dif from its 318 days and i really dont have the money to spend on a whole new 8 3/4 with a LSD or locker. I was wondering if drag slicks would do anything or if the open diff defeats the purpose (off of my mustang so its not a cost issue) Also i was wondering if i where to track down a 8 3/4 in the near future how do i change the wheel hub/brake assemblies at the ends and how are they narrowed? Would my best bet be finding something close in length and use it as a complete piece? If i make the 8 1/4 a suregrip with a mild 440 really break it? I know they are kind of general questions im just not sure where to go with it at this point. Thanks for any help/ opinions
-Tony

 

[72Satellite440]

Whats the application-street or strip?
How much power do you plan on pushing out/why do you need so much rubber on the road?

Why try to narrow a 8 3/4 that you find when you can go mini tub on your 72 charger and get a custom rim made to exact backspacing you need- more than enough rubber on the road

 

[Coronet 500]

I'm not sure what your trying to achieve when you ask about wheel hub/brake assembly changes. The 8 1/4" with slicks at the track will break, probably OK for some street hot rodding. If you do find an 8 3/4" I don't see any need to shorten it unless your going all out with tubs and huge tires. Your car with a stock width 8 3/4" proper back spaced wheel 10" slick, well up and inside the wheelwells will take all you could give it. An open differential will break before the limited slip as your putting all your power through only half of the it.

 

[Tang72]

Well i wouldn't want to minitub because its overkill on the car and its really a street car that only sees the track out of curiosity. Im only around 400 hp but when i launch i cant get traction whatsoever and slicks are a cheap performance gain (that i already have access to i just dont want to waste them.) Im just wondering if they will make a difference on an open diff car and if i will really break my 8 1/4 with only 400+hp. The questions about narrowing where just because i was unsure of whats normally done with junkyard 8 3/4s and how sensitive they are to width (if they where for example out of a truck, although my charger is already a very wide car so its probably unnecessary.)

 

[72Satellite440]

I think for that much HP your going to be fine with a 8 1/4 " axle- A good upgrade would be suregrip that way no matter the size of tires both are hitting the road.

 

[Coronet 500]

I agree with Satellite, your HP and occasional fun should be OK. The next thing is cost of improving the 8 1/4" or replacement. If you can do the work yourself, go for the sure-grip. If you stay with the same gear you can leave the pinion in, change the differential then adjust preload with side shims.

 

[Cranky]

As for not having a LSD in the rear, you can help the open unit you have by preloading the right rear. Some of the ways to do that is to turn up the left front torsion bar. This will add weight to the right rear. You can also add a leaf to the right rear, add weight in the right side of the trunk, like move your battery there. I used to run air shocks with about 5 psi in the left and 15 in the right and with my battery in the trunk, it would act like it had a LSD in it. Here's the reason why a non LSD rear spins the right rear tire....the rear end tries to torque over counterclockwise which makes the right rear try to raise up and plants the left rear into the ground...thus wheel spin on the right side only. As for the 8 1/4 holding up....I've trashed 9 1/4's before with less horse power. It just depends on how you abuse it. I'm VERY hard on my junk and have been known to do neutral drops, nail reverse while still going forward doing 30, huge static burnouts, catching air with the throttle matted....and the list goes on So, an 8 1/4 wouldn't do it for me lol

 

[YY1]

I can get 8 3/4 housings periodically (bought one today, minus backing plates, for $20), it's the centers that are getting pricey, especially SG. I seiously doubt a 72 needs tubs with all that wheel well space. You should be able to get a 300 series tire in there, maybe even a 17 inch, on a 10 or 12" wide rim at several different backspacings without any problem.

Look at wagons, as the length and perch are similar to the post 70 B size. Might have to get perches moved. Shouldn't cost much.

9 1/4 might be an option as well. If you want to run 6 lugs, you could get a Dakota 9 1/4 and there are 3:55 and 3:91 SG units at U-Pulls for about $400.

 

[YY1]

...I see 8 1/4 SG units for $125 and up. EB and CL.

Not quite as easy to work on as an 8 3/4, but still.....