8 3/4 vs. Dana 60
#2682912
07/30/19 10:27 PM
07/30/19 10:27 PM
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Joined: Aug 2007
Posts: 2,356 Kentucky
dfsmopars
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I moved over from the previous discussion on upgrades because I do see that before I move on with adding power I need to assure the rear end is ready for it. The Tremec is supposed to be good for 600 hp so we’re plenty good there. The 8 1/4 has endured what I have thrown at it so far but I am going on the experience of others about its limits.
So of course the 8 3/4 and Dana 60 were thrown out there. I am well aware of the capability of the 8 3/4 and am familiar with the set up and adding disc brakes to it. For me, straight forward.
But the Dana I thought was too much rotating mass and may be an overkill for a small block at even 450 hp with a manual trans.
How available are the right housings and center sections (3.91 gear with ls) going to be for each type? (Going in a third gen b-body) Is there going to be a difference in the cost to build each one? Is there a wow factor with the Dana over the Chrysler unit? Besides strength or longevity will one perform better than another in different situations such as street, auto cross and 1/4 mile? Will narrowing one be easier than the other?
If I have not mentioned something that should be mentioned please bring it up. Thanks!
‘72 Charger, 5.9 Magnum, Tremec 5 spd., Pro-Touring ‘14 Big Horn, Quad Cab, 4x4, 1500
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Re: 8 3/4 vs. Dana 60
[Re: dfsmopars]
#2683053
07/31/19 11:31 AM
07/31/19 11:31 AM
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Joined: Dec 2003
Posts: 23,273 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
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One detail not mentioned, is current tire and/or future tire choice. I would think an 8.75 would handle anything a 8.25 is currently handling. There is one upgrade to the 8.75 I would suggest other then well assembled with quality R&P, are upgraded cap(S). a rear brace IMO does little to promote 8.75 member longevity, but it does stiffen the housing, which if that is an issue, you are already in Dana country. Based on what you shared so far, my choice confidently would be the 8.75. The key metrics here are IMO, car weight, engine torgue, transmission, tire package, future possible upgrades, and intended use.
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: 8 3/4 vs. Dana 60
[Re: lewtot184]
#2683066
07/31/19 12:05 PM
07/31/19 12:05 PM
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Joined: Dec 2007
Posts: 18,165 Mass
DAYCLONA
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I've shucked 8 3/4 ring and pinions with a 383 4spd. maybe an 8 3/4 will hold up; maybe not. a lot of factors to consider. if you do an 8 3/4 and rip it the initial cost and repairs will be more than the initial cost of a dana. Same here, I've toasted quite a few 8 3/4 rears, even behind a few 340/4spds's..... DANA 60, end of story
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Re: 8 3/4 vs. Dana 60
[Re: DAYCLONA]
#2683068
07/31/19 12:08 PM
07/31/19 12:08 PM
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Joined: Aug 2011
Posts: 2,904 Pattison Texas
CSK
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I've shucked 8 3/4 ring and pinions with a 383 4spd. maybe an 8 3/4 will hold up; maybe not. a lot of factors to consider. if you do an 8 3/4 and rip it the initial cost and repairs will be more than the initial cost of a dana. Same here, I've toasted quite a few 8 3/4 rears, even behind a few 340/4spds's..... DANA 60, end of story THIS ^^^^^^^^
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: 8 3/4 vs. Dana 60
[Re: CSK]
#2683137
07/31/19 03:28 PM
07/31/19 03:28 PM
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Joined: Jan 2003
Posts: 13,492 Marion, South Carolina [><]
an8sec70cuda
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I've shucked 8 3/4 ring and pinions with a 383 4spd. maybe an 8 3/4 will hold up; maybe not. a lot of factors to consider. if you do an 8 3/4 and rip it the initial cost and repairs will be more than the initial cost of a dana. Same here, I've toasted quite a few 8 3/4 rears, even behind a few 340/4spds's..... DANA 60, end of story THIS ^^^^^^^^ Build a Dana and you're done. Building a dana from a junkyard truck rear can be done cheap. Especially if you get one w/ the good track-lock diff. It'll have either 3.54 or 4.10s gears in it already most likely. The one I put in my dad's road runner came from under an old dodge motorhome/camper van of some sort. Had the good track lock diff and 3.54s w/ a 1350 yoke surprisingly. All we did was narrow it, weld on pass. car ends and perches, and get some 35 spline axles from Dr. Diff. As well as his track-lock rebuild kit w/ the 35 spline side gears. Backbraces and billet caps for an 8.75 are "feel good" parts. May make you feel better, but do nothing to keep it from shredding the ring and pinion.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 4 speed, Dana 60 '71 Demon 340, no drivetrain, on blocks behind the barn '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: 8 3/4 vs. Dana 60
[Re: Mr.Yuck]
#2683178
07/31/19 06:27 PM
07/31/19 06:27 PM
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Joined: Aug 2007
Posts: 2,356 Kentucky
dfsmopars
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what is the car being used for? If you aren't frag racing dropping the hammer at 6k the 8.75 will be fine. If it makes you feel safer back brace it. Looks like a road racing car, a dana adds weight. My old 440-6 Charger went 11.20's @ 121+ had a 8.75 and 3.91's no issues at all. That was much more than 450...not too mention the added torque of a 440. Well it’s a car that is a “jack of all trades and a master of none”. It has a full interior and tips the scale at 3900 lbs. Once a year on the strip and once on an auto cross. Never slicks. Has to be suited for out of state road trips. It is not shown at car shows but frequents regional cruise ins. It sometimes gets hammered pretty good on the streets when the coast is clear. It needs to gain the respect of serious car people whether at Mopar events, the Hot Rod Power Tour or Good Guys. The hp and tq of the current small block will be increased to the goal of 450 for each power measurement hopefully after the rear end improvement. I am slow about making improvements since it is just a hobby but I will spend a little more dough to make the improvement the right one and not cheap out.
‘72 Charger, 5.9 Magnum, Tremec 5 spd., Pro-Touring ‘14 Big Horn, Quad Cab, 4x4, 1500
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Re: 8 3/4 vs. Dana 60
[Re: an8sec70cuda]
#2683187
07/31/19 07:17 PM
07/31/19 07:17 PM
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Joined: Dec 2003
Posts: 23,273 Here
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
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Here
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Backbraces and billet caps for an 8.75 are "feel good" parts. May make you feel better, but do nothing to keep it from shredding the ring and pinion.
Except the end result of a failed cap is, a "shredded ring and pinion".
" All sorts of things can happen when you are open to new Ideas" Inventor of Kevlar
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Re: 8 3/4 vs. Dana 60
[Re: gtx6970]
#2683191
07/31/19 07:36 PM
07/31/19 07:36 PM
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Joined: Aug 2011
Posts: 2,904 Pattison Texas
CSK
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3900 lbs and manual trans will not be the issue. UNLESS its spends a lot of time on the drag strip
its when you pop a set of slicks on it and drop the hammer is when it will be testing the 8-3/4 's limits
for me personally it would come down to gear choices. And theres not much for the Dana in something street / hiway friendly But with an OD trans and a set of 3.54';s may not be bad for longer drives Dr Diff has 3.23 for the D60
Last edited by csk; 07/31/19 07:37 PM.
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: 8 3/4 vs. Dana 60
[Re: dfsmopars]
#2683201
07/31/19 07:59 PM
07/31/19 07:59 PM
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Joined: Aug 2003
Posts: 43,719 Bend,OR USA
Cab_Burge
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[quote= The hp and tq of the current small block will be increased to the goal of 450 for each power measurement hopefully after the rear end improvement. I am slow about making improvements since it is just a hobby but I will spend a little more dough to make the improvement the right one and not cheap out. That is one of the best ways to save time, effort and money Some people never learn this Do it correctly ,ONCE
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 8 3/4 vs. Dana 60
[Re: gtx6970]
#2683223
07/31/19 09:00 PM
07/31/19 09:00 PM
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Joined: Aug 2007
Posts: 2,356 Kentucky
dfsmopars
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for me personally it would come down to gear choices. And theres not much for the Dana in something street / hiway friendly But with an OD trans and a set of 3.54';s may not be bad for longer drives The 3.55s in the 8.25 now are a bit too long. They were great with a 42RE I had in the car earlier but with the Tremec 70 mph and it’s only turning 1800 rpm. With the small block I have to wind it up to about 2000 rpm to leave from a stop light and not have to wait for the engine to take forever to catch up in order to shift to second. If that makes any sense. I had a Tremec six speed with 4.10s in another car that was great. That’s why I think 3.91s would be a good gear with this five speed. Can 3.91s be found for a Dana?
‘72 Charger, 5.9 Magnum, Tremec 5 spd., Pro-Touring ‘14 Big Horn, Quad Cab, 4x4, 1500
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