Moparts
Will I need to change My rear end??
Posted By: 70Dart499
Will I need to change My rear end?? - 02/10/13 09:47 PM
Will I need to change my 8 3/4 out in order to run a trans brake? My car weighs 3100 pounds and runs 6.80's, would probably run 6.70's with the brake. I would love to be able to switch to a tranny brake so I could run super pro, but I'm not liking the idea of having to buy a $3,000.00 moser rear end to do it.
Posted By: 68shifter
Re: Will I need to change My rear end?? - 02/10/13 10:30 PM
How stout is your 8-3/4 now. You could likely get by for a while but eventually on borrowed time.
You can get Dana's built for half of that. If your ladder bar consider a truck housing since the snubber provision isn't needed for you, and you already have brakes.
Good luck.
Posted By: 70Dart499
Re: Will I need to change My rear end?? - 02/10/13 10:36 PM
The 8 3/4 is pretty Stout, it's got a spool, moser axles, not sure on the gear, but I don't think it's a pro gear (I may be wrong but I don't think they make one for an 8 3/4). It's a stock case and thirdmember, and it's not backbraced. I don't like the idea of being on borrowed time, so I might just wait a footbrake race for a while longer until I can swap the rear for a Dana or a 9". Where might I find a Dana cheaper than moser & strange.
Posted By: hankcrank
Re: Will I need to change My rear end?? - 02/11/13 12:08 AM
Big blocks are hard on 8 3/4's and the trans brake would make things worse. Your car is not real heavy but still over 3,000. You might be OK if it was a lot lighter but if your goal is to run super pro it is normally a full tree so foot braking is competitive in that class.
Posted By: slippery440
Re: Will I need to change My rear end?? - 02/11/13 12:31 AM
Quote:
Will I need to change my 8 3/4 out in order to run a trans brake? My car weighs 3100 pounds and runs 6.80's, would probably run 6.70's with the brake. I would love to be able to switch to a tranny brake so I could run super pro, but I'm not liking the idea of having to buy a $3,000.00 moser rear end to do it.
And here we go!! 
Do everyone a favor and do a search. You will find atleast 100 post on this subject. 
I will not answer this question just for the reason someone eles will answer just the oposite way. This is the great debate. 
Posted By: J_BODY
Re: Will I need to change My rear end?? - 02/11/13 12:36 AM
I switched to a Dana 60 when I went to a t-brake in my Mirada just because I wanted to decrease my chances of scattering parts out back.
Posted By: J_BODY
Re: Will I need to change My rear end?? - 02/11/13 12:46 AM
....and we went to a D-60 in our small block Duster as it was running faster than the Mirada and we were twisting the 30 spline axles pretty hard. Rather than spend the $$ on new axles and matching spool, we just sold off our gear sets, and built a Dana.
Posted By: mopar65
Re: Will I need to change My rear end?? - 02/11/13 12:51 AM
Quote:
The 8 3/4 is pretty Stout, it's got a spool, moser axles, not sure on the gear, but I don't think it's a pro gear (I may be wrong but I don't think they make one for an 8 3/4). It's a stock case and third member, and it's not back braced. I don't like the idea of being on borrowed time, so I might just wait a foot brake race for a while longer until I can swap the rear for a Dana or a 9". Where might I find a Dana cheaper than moser & strange.
with a trans brake i would not waste your time trying to make a 8-3/4 live. i would go with a Dana 60 or 9 inch ford. when i built the Dana in my 65 Plymouth, i used the 60 out of a 78 3/4 ton ford truck. i sent the housing off to moser to have ends put on it.i think i had less than 1500 in the hole set up. OK my 73 dodge dart weighs 3520 with me in it.i have a stock stroke 440, with a back braced 8-3/4, 742 case, Richmond 4.10 gears moser 30 spline spool axles. right after i got the car running i took it to the track and blew up the 4.10 gears on my 5th pass. at time i was only running 1.58 60foots and 10.66 at 125 in the 1/4. i have sense then put Richmond 4.30 gears in and have ran a best 60 ft of 1.48 and a 10.49 at 125 in the 1/4. sorry for the long winded post just trying to say i don't see your 8-3/4 lasting very long with a trans brake and the power you are making. mopar65 
Posted By: mopar65
Re: Will I need to change My rear end?? - 02/11/13 12:52 AM
Posted By: MR_P_BODY
Re: Will I need to change My rear end?? - 02/11/13 12:53 AM
Quote:
The 8 3/4 is pretty Stout, it's got a spool, moser axles, not sure on the gear, but I don't think it's a pro gear (I may be wrong but I don't think they make one for an 8 3/4). It's a stock case and thirdmember, and it's not backbraced. I don't like the idea of being on borrowed time, so I might just wait a footbrake race for a while longer until I can swap the rear for a Dana or a 9". Where might I find a Dana cheaper than moser & strange.
Its not very stout if it isnt back braced... that
would be the first thing to do... I dont know if you
do your own work or not BUT if you dont you might
as well get a dana now... if you dont back brace a
8 3/4 your on borrowed time... if it hooks at all
the ends will bend forward
EDIT
I use a 8 3/4 on a trans brake... have for YEARS but
in a lighter car... I wont get into what others say
about the 8 3/4 but in a lite car they live fine
(doenst matter on the torque)......... JMO
Posted By: 70Dart499
Re: Will I need to change My rear end?? - 02/11/13 12:56 AM
Quote:
Big blocks are hard on 8 3/4's and the trans brake would make things worse. Your car is not real heavy but still over 3,000. You might be OK if it was a lot lighter but if your goal is to run super pro it is normally a full tree so foot braking is competitive in that class.
Super Pro around here is a full tree, and while I might be able to go some rounds at my local track, I won't be competitive at the big money bracket races without a t-brake and a delay box, not to mention I would like to try to run a few IHRA Hot Rod (aka NHRA Super Street 10.90 index) races in the future. Im shooting for eventually being able to double enter in both footbrake and super pro. It looks like a Dana is in order first though, thanks for the advice.
Posted By: Quicksilver440
Re: Will I need to change My rear end?? - 02/11/13 05:23 AM
You can build a Dana for under $1000 if your thrifty....even if you have one built it won't cost $3000....call Dr diff. My guess is $2000 tops.
Posted By: 70blackfish
Re: Will I need to change My rear end?? - 02/11/13 05:26 AM
trans brakes, and 8 3/4 Not good
....do a dana a be done with it..
Posted By: ChrisJohnston669
Re: Will I need to change My rear end?? - 02/11/13 06:03 AM
strange dana 60 is like 2000-2200
Posted By: astjp2
Re: Will I need to change My rear end?? - 02/11/13 06:27 AM
My dana was $50 for the housing out of a truck
$385 to narrow, install the torino ends by dutchman
$400 for 35 spline shafts
$85 for 3.55 dana gears
$175 for 35 spline power lock
$350 for bearing and install kit
$200 for explorer disk brake kit
I installed dana 70 gears in the 60 shousing, its a hybrid called a Jana 76, it was only about 150 more to do the conversion.
Tim
Posted By: Mr.Yuck
Re: Will I need to change My rear end?? - 02/11/13 02:06 PM
why not back brace it? That should help. 3100lbs is light enough.
Posted By: deaks
Re: Will I need to change My rear end?? - 02/11/13 03:49 PM
Another thing worth mentioning, is that selling the 8-3/4 before it's broke, will go along way to paying for the dana.
Mick
Posted By: Mr.Yuck
Re: Will I need to change My rear end?? - 02/11/13 04:23 PM
Another thing to consider is...is it really worth all that cost and work to pick up a tenth?
Posted By: DoctorDiff
Re: Will I need to change My rear end?? - 02/11/13 04:33 PM
A brand new bolt-in Dana 60 with 35 spline axles, spool, choice of ratio and 1350 yoke runs $1800.
You can re-use your old brakes.
Posted By: JohnRR
Re: Will I need to change My rear end?? - 02/11/13 05:33 PM
Quote:
why not back brace it? That should help. 3100lbs is light enough.
Because in the end the weak link is still the GEARS , see the picture above .
Posted By: Thumperdart
Re: Will I need to change My rear end?? - 02/11/13 05:52 PM
Quote:
Quote:
why not back brace it? That should help. 3100lbs is light enough.
Because in the end the weak link is still the GEARS , see the picture above .
I definately say a prayer and cross my fingers every time I leave the burnout box and stage.............8 3/4, stock caps, backbrace and 30 spline axles and at 3200 lbs to boot however, no dana under my car and I should be at or around 3000 lbs. soon........ 
Posted By: Mr.Yuck
Re: Will I need to change My rear end?? - 02/11/13 06:07 PM
Quote:
Quote:
why not back brace it? That should help. 3100lbs is light enough.
Because in the end the weak link is still the GEARS , see the picture above .
yup I did the same to a 30+ year old set of 3.91 when 6 psi of boost was added to the mix. replace w/ a nodular from randy's and fresh set of Yukons and zero isses. 3850lb 12.0 car.
Posted By: Bigbeep
Re: Will I need to change My rear end?? - 02/14/13 05:54 AM
Mark, where are you located? If anywhere near central ohio, I can help with fab work narrowing a truck housing. I have a narrowing jig to do just about any of the common axle/end combinations. I too used a dana from a truck and other than the tubes being thicker they are great. If it is leafsprung you may need 3 1/8" u-bolts and modify your lower shock mount/sping plate holes and new perches.
hope this helps. Beep
Posted By: Gabby63
Re: Will I need to change My rear end?? - 02/14/13 07:14 AM
I have to agree that you will not last long with the 8 3/4 , I had one that was back braced with spool & great gears in my 3450 lbs 63 , it did not last 8 races , went with the Dana 60 . My focus is not in the rear end now , just my 02 . Gary
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