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How much power can a 8.75 rearend handle? #1094420
10/14/11 07:11 PM
10/14/11 07:11 PM
Joined: May 2010
Posts: 171
Georgia, United States,
Crock Offline OP
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Crock  Offline OP
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Joined: May 2010
Posts: 171
Georgia, United States,
Well I have a promotion to Ssgt(USMC) and reenlistment bonus coming the beginning 2012 so I'm about to either purchase the 426 short block or supercharge my current setup. I'm trying to come up with the best bang for my buck.

Quick Overview: Restomod 66 Plymouth Belvedere
My entire build 6.1 Hemi, 727 torque flight/B &M shift kit/ported and polished intake/ported and polished heads/ TTI long tube headers/ 180 thermostat/SLP under drive pulley/741 housing /3:55. Gears/Detroit True-trac sure grip/power steering delete pulley/ B & M 2400-2800 stall converter non lock up, 90 mm TB with nitrous injector, cold air intake, catch can, Cam specs Intake Duration 267 Lift .583 Exhaust Duration 270 Lift .566.

This is what I posted on the SRT forums and a response I got back was. "You also should think about the capacity of your 727 and rear."
Well I asked about the 727 a while back and found out they are really they can hp and tq in the ranges of 700 to 800 with stock parts and upgraded value body but my question is what will the stock 8.75 rear end with stock axles handle? Also what other weak leaks do you see if any?
People have boosted that the 6.1 block bored to 426ci supercharged will make 600 or better.

Re: How much power can a 8.75 rearend handle? [Re: Crock] #1094421
10/14/11 07:34 PM
10/14/11 07:34 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
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MR_P_BODY  Offline
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Posts: 52,972
Romeo MI
What will the car weigh... my opinion its weight that
kills a 8 3/4.... this same question is asked ever
other week.... you could try the search

Re: How much power can a 8.75 rearend handle? [Re: MR_P_BODY] #1094422
10/14/11 08:27 PM
10/14/11 08:27 PM
Joined: Nov 2009
Posts: 2,177
ill
D
dennismopar73 Offline
top fuel
dennismopar73  Offline
top fuel
D

Joined: Nov 2009
Posts: 2,177
ill
it can handle all of it right before it breaks !!
, weight n hp as mr p says
i would think, livable under 600 hp at the wheel, on a 3000@ car just guess

ok i rethink that, if stock axels, and stock rear, under 450 hp i twisted axels on my volare with a basic stock 440 running 11.90
wiegth was 3560

Last edited by dennismopar73; 10/14/11 08:35 PM.
Re: How much power can a 8.75 rearend handle? [Re: Crock] #1094423
10/14/11 10:10 PM
10/14/11 10:10 PM
Joined: Jan 2003
Posts: 8,016
Polson, MT
DoctorDiff Offline
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Polson, MT
Anything with 375 hp and a 4-speed came with a Dana 60 from the factory.

Re: How much power can a 8.75 rearend handle? [Re: DoctorDiff] #1094424
10/14/11 10:17 PM
10/14/11 10:17 PM
Joined: Nov 2009
Posts: 2,177
ill
D
dennismopar73 Offline
top fuel
dennismopar73  Offline
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Posts: 2,177
ill
not everything,
dana was an option on alot of the cars ,
and not all 440- 4 speed cars for sure,
we ran deep into the 10 with stock rear ends, after market axles
i even know couple guys running in the mid 11 with resplined ,
i do not recomend that for sure,
had more issues with u joints than rears,

Last edited by dennismopar73; 10/14/11 10:21 PM.
Re: How much power can a 8.75 rearend handle? [Re: dennismopar73] #1094425
10/14/11 10:22 PM
10/14/11 10:22 PM
Joined: Jul 2008
Posts: 30,247
Florida STAYcation
dIc dOc Deity ! Offline
The village idiot's idiot
dIc dOc Deity !  Offline
The village idiot's idiot

Joined: Jul 2008
Posts: 30,247
Florida STAYcation
And then back-in-the-day ... MOST T/F cars had an 8 3/4 ... with 2500 hoes-power ....

BUT ... they never really hooked-up ...

Re: How much power can a 8.75 rearend handle? [Re: dIc dOc Deity !] #1094426
10/14/11 10:34 PM
10/14/11 10:34 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
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Posts: 52,972
Romeo MI
Quote:

And then back-in-the-day ... MOST T/F cars had an 8 3/4 ... with 2500 hoes-power ....

BUT ... they never really hooked-up ...




I've been very happy with my 8 3/4... its a alum
center now but I use to run a stock center with a
stock cone posi....... and thats a 1.19 60'... but
my car is light

Re: How much power can a 8.75 rearend handle? [Re: Crock] #1094427
10/14/11 10:45 PM
10/14/11 10:45 PM
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck Offline
Not enough dumb comments...yet
Mr.Yuck  Offline
Not enough dumb comments...yet

Joined: Jan 2003
Posts: 24,562
Brookeville, Md
It will be fine that 6.1 doesn't make enough power to break that 8.75. I ran my junk to 11.39 w/ stock axles, stock ring/pinion no worries.


[IMG]http://i66.tinypic.com/pui5j.jpg[/IMG]
Coming soon!!!!
Re: How much power can a 8.75 rearend handle? [Re: Mr.Yuck] #1094428
10/14/11 11:17 PM
10/14/11 11:17 PM
Joined: Jan 2007
Posts: 437
south central pa
bdaz smblk Offline
mopar
bdaz smblk  Offline
mopar

Joined: Jan 2007
Posts: 437
south central pa
The 8 3/4 will take it but the 741 case is the weakest one you can get.


3120lb, small block, 10.5" tire, NA, through exhaust, full int, WITH 83/4 REAR, 9.0 at 150mph
Re: How much power can a 8.75 rearend handle? [Re: dennismopar73] #1094429
10/14/11 11:41 PM
10/14/11 11:41 PM
Joined: Jan 2003
Posts: 8,016
Polson, MT
DoctorDiff Offline
master
DoctorDiff  Offline
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Posts: 8,016
Polson, MT
All 440/4-speed B and E bodies and all '66-'71 426/4-speed cars came with a factory installed Dana 60 rear.

A Dana 60 was optional behind some 440/426 automatic cars.

Even the super rare 440/4-speed C-body came with a Dana 53 rear.

Re: How much power can a 8.75 rearend handle? [Re: DoctorDiff] #1094430
10/15/11 02:53 AM
10/15/11 02:53 AM
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
tubtar Offline
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tubtar  Offline
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St. Paul , Mn.
I have to side with Mike here..........weight and hook are what kills them.
The factory was worried about longevity and heavy footed kids costing them a ton on warranty work or they would not have spent any extra by installing 60's in cars.
They have a good point.
But an 8 3/4 will take a lot if it is set up right.
Back brace , aftermarket cap and axles make them a heck of a lot tougher than how they left the factory.
Not Dana tough , but pretty sturdy.

Re: How much power can a 8.75 rearend handle? [Re: Crock] #1094431
10/15/11 06:03 AM
10/15/11 06:03 AM
Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar Offline
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451Mopar  Offline
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Joined: May 2008
Posts: 5,399
Aurora, Colorado
The stock 8-3/4" will take alot of power with an automatic trans. Once into the 11's and quicker you may be pushing it. Cost wise, I think the Strange S60 is less expensive than upgrading the 8-3/4" with all the performance parts?

Re: How much power can a 8.75 rearend handle? [Re: 451Mopar] #1094432
10/15/11 08:01 AM
10/15/11 08:01 AM
Joined: Mar 2003
Posts: 1,629
pa
572charger Offline
top fuel
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Posts: 1,629
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our 3400lb cuda ran 11ohs and 10.90s we changed the ring and pinion about every 60 passes [3times] till we got a dana in it that was back in the 80s we were on a budget, ported 906s trws 30 over and the best cam of all time 590 purple shaft


606 hemi pump gas best 9.60 at 142mph on motor
05 hemi daytona 1500 go-mango 4wd quadcab
2007 hotrod mag pump gas drags runner up, roadkill nights dodge big tire winner 2018 2019 back to back
Re: How much power can a 8.75 rearend handle? [Re: Mr.Yuck] #1094433
10/15/11 10:19 AM
10/15/11 10:19 AM
Joined: Jan 2003
Posts: 27,421
Balt. Md
3
383man Offline
Too Many Posts
383man  Offline
Too Many Posts
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Posts: 27,421
Balt. Md
Quote:

It will be fine that 6.1 doesn't make enough power to break that 8.75. I ran my junk to 11.39 w/ stock axles, stock ring/pinion no worries.




Same here all stock 8-3/4 but with my 493 I am starting to worry. When my funds let me I plan to go to a Dana. Ron

Re: How much power can a 8.75 rearend handle? [Re: bdaz smblk] #1094434
10/15/11 10:46 AM
10/15/11 10:46 AM
Joined: Dec 2003
Posts: 22,695
Bitopia
J
jcc Offline
If you can't dazzle em with diamonds..
jcc  Offline
If you can't dazzle em with diamonds..
J

Joined: Dec 2003
Posts: 22,695
Bitopia
Quote:

The 8 3/4 will take it but the 741 case is the weakest one you can get.




However that might be splitting hairs, as I suspect anything a 741 will not handle, a 742 is not not far behind in also being overpowered. Biggest drawback IMO to a 741 is likely avaliable gears and having a big aversion to bypassing a 742 and going with a Dana.

Last edited by jcc; 10/15/11 10:50 AM.

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
Re: How much power can a 8.75 rearend handle? [Re: 383man] #1094435
10/15/11 10:46 AM
10/15/11 10:46 AM
Joined: Feb 2004
Posts: 6,257
acworth / N. georgia - south e...
cheapstreetdustr Offline
master
cheapstreetdustr  Offline
master

Joined: Feb 2004
Posts: 6,257
acworth / N. georgia - south e...
Say no to stock axles...yank em..and get aftermarket..
or youll be building a new car ...
a broken axle will put you on your lid...
Dont listen to anyone who says stock axles will be fine..if you can't afford $175.00 axles..
you cant afford to run the car..IMHO..

ive seen them break twist and sheer on 6cyl cars with slicks..

my

fwiw..Im going 10.60's 3280lbs on a mark williams built 8.75 rear..


365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured
[image][/image]
Re: How much power can a 8.75 rearend handle? [Re: cheapstreetdustr] #1094436
10/15/11 01:53 PM
10/15/11 01:53 PM
Joined: May 2010
Posts: 171
Georgia, United States,
Crock Offline OP
member
Crock  Offline OP
member

Joined: May 2010
Posts: 171
Georgia, United States,
Let me clear up a couple things. My car originally was a slant 6 car with the 8.25. I remove it and replaced it with the 370ci 6.1 Hemi. First I had fun with the 8.25. and 293 ring and pinion the car was so fast on the top end that the car would float from side to side it was very scare but after that I upgraded to heavy duty springs and aftermarket pinion bump stop. I replaced the 8.25 with a friends 8.75 in a car he was taking to have crashed. I've already had trouble finding a stronger yoke for the 741 case. What is the strongest case out of the 741, 742, and 489? Is the 741 exterior its weak point and if so anything to help it or upgrade to a different case.

I plan on stroking the 6.1 to a 426ci hemi and adding the supercharger to create 600 hp to the rear wheels.

The car is a street car full interior so i estimate it weights 3600. Engine was 800 pounds out the crate. Currently has a 8.75 with 3.55 ring and pinion.

Axles, back braces anything else I need to strength this rearend. I already have rear disc brakes to stop this breast.

Re: How much power can a 8.75 rearend handle? [Re: Crock] #1094437
10/15/11 05:05 PM
10/15/11 05:05 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
C
Cab_Burge Offline
I Win
Cab_Burge  Offline
I Win
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Joined: Aug 2003
Posts: 43,007
Bend,OR USA
Quote:

Let me clear up a couple things. My car originally was a slant 6 car with the 8.25. I remove it and replaced it with the 370ci 6.1 Hemi. First I had fun with the 8.25. and 293 ring and pinion the car was so fast on the top end that the car would float from side to side it was very scare but after that I upgraded to heavy duty springs and aftermarket pinion bump stop. I replaced the 8.25 with a friends 8.75 in a car he was taking to have crashed. I've already had trouble finding a stronger yoke for the 741 case. What is the strongest case out of the 741, 742, and 489? Is the 741 exterior its weak point and if so anything to help it or upgrade to a different case.

I plan on stroking the 6.1 to a 426ci hemi and adding the supercharger to create 600 hp to the rear wheels.

The car is a street car full interior so i estimate it weights 3600. Engine was 800 pounds out the crate. Currently has a 8.75 with 3.55 ring and pinion.

Axles, back braces anything else I need to strength this rearend. I already have rear disc brakes to stop this breast.


The 742 case is the best for hot rodding, a Dana 60 is way better If you must or insist on using the 8 3/4 rear buy a steel cap and a steel billet yoke for the pinion gear. Mu street car made 564 hp to the rear wheels on a Mustang chassis dyno with the 8 3/4 in it with 3.91 gears, i ended up breaking them, I broke a set of 4.10 and some other gear sets. I finally bent the housing so bad(no back brace)that it pulled the welds loose on the ladder bar mounts, I had a real hard time getting the right side axle out after it broke also, the right side is bent so bad from the center out to the backing plates you can see it I bought a used Dana 60 from a 3/4 ford pick up (3.1/4 thick diameter axle tubes ) and had it narrowed, put the ladder bars mounts back on it and put the Mopar axle bearing ends on it so I cuuld reuse the same brakes and axles I used a used set of dana Corp 4.10 and a new Strange Engr. 35 spline spool. My car(1971 Duster, original six cylinder witha pump gas 518 low deck stroker) car weighs 3450 with me inn it with teh 8 3/4, I haven't reweighed it since adding the Dana so it may weigh another 10 to 40 lbs now, probally around 20 lbs more The car pushes(by hand by me) way easeir than it ever did with the 8 3/4


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: How much power can a 8.75 rearend handle? [Re: Cab_Burge] #1094438
10/16/11 12:47 PM
10/16/11 12:47 PM
Joined: Jan 2004
Posts: 550
Ma
Voluster Offline
mopar
Voluster  Offline
mopar

Joined: Jan 2004
Posts: 550
Ma
I just went 9.59 at 139 with a 1.36 60 ft last weekend with a 8 3/4 on a drag raidal

We figured 720 hp the car weighed 3460


Re: How much power can a 8.75 rearend handle? [Re: Crock] #1094439
10/16/11 01:09 PM
10/16/11 01:09 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
Quote:

Let me clear up a couple things. My car originally was a slant 6 car with the 8.25. I remove it and replaced it with the 370ci 6.1 Hemi. First I had fun with the 8.25. and 293 ring and pinion the car was so fast on the top end that the car would float from side to side it was very scare but after that I upgraded to heavy duty springs and aftermarket pinion bump stop. I replaced the 8.25 with a friends 8.75 in a car he was taking to have crashed. I've already had trouble finding a stronger yoke for the 741 case. What is the strongest case out of the 741, 742, and 489? Is the 741 exterior its weak point and if so anything to help it or upgrade to a different case.

I plan on stroking the 6.1 to a 426ci hemi and adding the supercharger to create 600 hp to the rear wheels.

The car is a street car full interior so i estimate it weights 3600. Engine was 800 pounds out the crate. Currently has a 8.75 with 3.55 ring and pinion.

Axles, back braces anything else I need to strength this rearend. I already have rear disc brakes to stop this breast.




Mark Williams caps, back brace and after market axles...
thats a heavy car to have a 8 3/4 live in

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