8 3/4 rear end .strong enough?

[mr.mopar]

hello
i have a 528 hemi and a manual transmission.i have a 8 3/4 rear end 489 case.an original rear end for an 70 challenger rt.i also have a 489 case with 4.30 that i'm going to use.what is recomended to do with the rear end to handle the 650lb of torq that is in the hemi engine.spool and moser axles,is that enough? 

[KellysCuda aircard]

You will be on the ragged edge man...as I am with my 8 -3/4.  Either a dana or ford 9" next.  I run detroit locker (auburn wouldnt take the punishment), moser axils and green bearing kit.

[Chryco Psycho]

I would spend the $$ on a Dana 60 , the 8 3/4 will not live long & you wil be spending the $$ twice

[MG440RT]

Chrysler used 8 3/4 rear ends on the early S/S and A/FX cars...didn't last forever but your car wont be taking that kind of punishment anyways...

[Chryco Psycho]

make sure you replace the crush sleeve with a spacer if you use the 489 diff

[ShelbyDogg]

If you ever put any real slicks on it and get traction on a sticky starting line, that 8-3/4 will blow right at the ring gear teeth.  Do it right the first time and spend the money on a dana.   Why spend it twice?

[72hemi]

One of the regulars at my local dragstrip has a 10 second 68 big block dart, and he told me that he was blowing 8 3/4 all day long when he installed the transbrake (it was fine before with slicks and no transbrake). He finally went with a dana and hasn't broken one yet.

[Chryco Psycho]

the 8 3/4 diff in my Cuda lasted approx 50 " , it ripped 37 teeth off the ring gear on the first launch

[tactransman]

I had an 8 3/4 and 12 inch slicks,spool and Moser axles in the Duster I dragged for a couple of years. It ran 10.40's/1.42 60 ft and did a little wheelie off the the line. Never failed on me.(It did only weigh 3000 lbs though)

[ShelbyDogg]

My Arrow only weighed 2375 lbs and I had a 14" slick with 4:88 gears.   It lasted about a year and it breaking cost me a race that day. It was behind a MILD 440. The Dana replacement lasted the remaining 9 years that I raced and was still okay when I sold the car.

8-3/4s should be okay for street tires!  A track starting line is different from ANYTHING on the street.

[tactransman]

Rob, did you run a trans brake? An 8 3/4 will definitely give way to a trans brake.

[ShelbyDogg]

I wasn't using a t/brake when the ring gear broke. I was only using a 3500 stall 10" converter and  foot-braking it.  After I switched to the Dana, I then went to a trans-brake and a Turbo Action "J" converter.

[tactransman]

 

  A track starting line is different from ANYTHING on the street.

[mr.mopar]

hello
i bought a dana 60-hd axle from a van.it has 4.10 and sure grip.30 splines.i have bought a new 35 splines sure grip from a friend and got new 35 splines axles from a guy in usa.now i'm going to put some new axle tubes on and bay some brakes.thanks for the answers
 
runar

[ShelbyDogg]

Mr.Mopar,

You will be happier after the switch.  You can also change it back after you find another car later.     One more thing, when you have your u-joints assembled,  make sure that the joint is compressing the area that contains the grease-zerk opening and not trying to pull it apart. The front and rear.  If you do that, they will never fail.