8 3/4 info

[Chryco Psycho]

http://www.planethoustonamx.com/main/chrysler_8_34_rearends.htm

[cudaragtop]

More...
http://www.mopardealer.com/rearends.htm

[redgum78]

Good info there 

[303 Mopar]

So the questions remain which is stronger the 742 or the 489?  And how much HP and TQ can an 8 3/4 handle before you need to switch to a Dana? 

[Burdar]

The 8 3/4 can handle a lot on the street.  It's downfall is slicks on a sticky track and a manual trans.

Dr Diff feels that the 741 is a lot stronger then people give it credit for.  It has a small bearing but the shaft doesn't taper...no stress riser.

http://www.moparts.org/Tech/Archive/axle/1.html

[70/6chall]

While we're talking about the 8 3/4 rear ends here, I'll relate this story. Several years ago, the 7 1/4 rear axel in my '70 Challenger decided to start howling, late 80's, early 90's. As this was my daily driver, I had to come up with something real quick. A friend located an 8 3/4 for an E-body for me, so for $50. I had ready to hang an 8 3/4 out of a big block '71 Challenger, with a one legger 742 carrier, 3.23 gear set, 11" brakes. Overkill, probably, but hey! $50. ready to go and it's still up under there. My SL6 will die before the rear end does.        Thanks,   Al

[Chryco Psycho]

Well My experience tells me the same , traction is the killer
My Duster was 550+ HP , probably similar tq ... but hooked up hard , 60' in 1.40 lifting the front wheels 2'
I would crush the sure grip gears approx yearly , the ring & pinion held up fine!
it was a 489 with 4.30 gears
I transferred the drivetrain into my tube chassis Cuda / no chassis flex / no clutch slippage as I used a much better clutch / no tire slippage as I went up to 14x32" from a 10.5 X 29" tire
I only made it 40" , not even 1 full rotation as the pinion tore 37 teeth off of the ring gear before all the pinion teeth were gone too .
I doubt you can hurt an 8 3/4 if the tires spin !

[RUNCHARGER]

I pulled the axles on this car just in time, they were twisted pretty good, I never ran it with slicks. I have no problem running a 741 case either and people give them away.

[dodj]

The 8 3/4 can handle a lot on the street.  It's downfall is slicks

I think the 8 3/4 is plenty strong for a street tire shod car.

[340challconvert]

As I go through my car, cleaning up the rear 8 3/4
It is a 489 case and the numbers stenciled on the carrier are 10   22
I am thinking this is the inspection date for the carrier October 22?
The other number above the cast part number appears to be an 8?

The paint markings are still very visible too:  white w orange indicates a 3:55 with sure trac
Just curious on the stenciled numbers; do they indicate a date, car was an early to late October assembly?

[Shane Kelley]

The rusty unit it out of a 7/71 car (RoadRunner) and the orange oxide one is out of a 10/70 car (Cuda).  Curious to see if someone knows your answer.