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#1 |
Senior Member
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Location: Omaha Nebraska
Posts: 588
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Which brand of posi
I’m running a 496 in my 72 c10 with a turbo 400 and 373 rear gear. I do not want to go to a overdrive trans but I’m looking for a more highway friendly rear gear. Planning on going with 308 but looking for advice on what brand of posi is everyone using with good luck??
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#2 |
Senior Member
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Location: Portland - OR
Posts: 243
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Re: Which brand of posi
I like eaton
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#3 |
Registered User
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Location: Nor Cal
Posts: 822
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Re: Which brand of posi
I have used Eaton on two rear ends with great results.
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1968 C20 Fleetside 396 4sp PS PB AC CST . https://www.youtube.com/watch?v=RWK8GgWD4uA |
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#4 |
Senior Member
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Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
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Re: Which brand of posi
Eaton...Eaton was OEM back in the day. I run them in both my 72's and have yet to wear one out. I have one with 150K + miles on it and it still works great behind my built 427 BBC with a 4:56...
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" ![]() "Be American, Buy American" ![]() Last edited by Ironangel; 10-22-2019 at 11:19 AM. |
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#5 |
Senior Member
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Location: Colfax-California
Posts: 8,526
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Re: Which brand of posi
Tru-trac all the way
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#6 |
Senior Member
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Location: Portland - OR
Posts: 243
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Re: Which brand of posi
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#7 |
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Location: 2nd left past the stump on a dirt road.
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Re: Which brand of posi
I have 2 acquaintances that have utilized the Tru-trac units. A bit spendy at first but worth it in the long run.
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#8 |
Registered User
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Location: KINGSPORT,TN.
Posts: 3,035
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Re: Which brand of posi
Simple, eaton
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#9 |
Account Suspended
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Location: Tacoma, WA
Posts: 6,873
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Re: Which brand of posi
Yukon makes an exact copy of the eaton unit, great quality and sometimes with rebates.
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#10 |
Registered User
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Location: KINGSPORT,TN.
Posts: 3,035
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Re: Which brand of posi
Yukon is china, be advised
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I BELIEVE IN JOHN 3:16 |
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#11 |
Registered User
Join Date: Jul 2019
Location: Rep City, Nebraska
Posts: 2
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Re: Which brand of posi
Sorry to hi-jack.. but i just got in a new spider gear kit for the 67 in working on currently. It has the Eaton Posi unit and i am needing to replace the chewed up spider gears and everything that goes with doing the task. Is it possible one of yall has a link for a good write up on bssically a full rebuild for the 12 bolt truck rear end? Tools required? Think all i need is a mag based dial indicator.. But...I have never taken on the task before, n just want to be confident with fhe finished result. I appreciate any helpful advice. (Pic Below) 6.0/80e, cam, converter, Single stg. N²O.. Once i get the 12bolt done i can finish tuning it 🇺🇸
Thank you! Adam |
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#12 |
Registered User
Join Date: Jul 2019
Location: Rep City, Nebraska
Posts: 2
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Re: Which brand of posi
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#13 |
70+ ( Old Skool Club )
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Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,119
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Re: Which brand of posi
Just put a Tru-Trac in my 72 this past summer and am happy with it. I find on cornering it keeps both wheels gripping the same.
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1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021 |
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#14 |
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Re: Which brand of posi
I put an Auburn Posi, new 3.08 ring and pinion, and new axles in my 71 rear end. With labor it was $1900 bucks. I'm very happy with it.
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#15 |
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Location: Omaha Nebraska
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Re: Which brand of posi
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#16 |
Senior Member
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Location: New Palestine In
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Re: Which brand of posi
I'm running a 355, 350 bored .030 over, with domed pistons. Edelbrock manifold, 600 CFM carb, and cam is a little over stock. I'm guessing maybe 270 HP. Tubo 350 trans. The truck is plenty peppy and does well at 70 MPH on the interstate.
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Phil "Money is only a tool to create and achieve what you want most in life" PayPal: rodnrudy@comcast.net |
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#17 |
Registered User
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Location: Pittsburgh, PA
Posts: 204
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Re: Which brand of posi
If you want a clutch-style Posi, Eaton was the original supplier and is basically identical nowadays save for the clutch material (now that are carbon instead of what I am sure was some type of asbestos-containing stuff, back in the day). Plenty strong, but does need a friction modifier. Very streetable, soft engagement.
Detroit TrueTrac is a bit more aggressive, no wearable parts, no friction modifier, stout as heck. That being said, I put an Eaton in mine when I rebuilt it. Can't go wrong either way, but having driven both, I prefer the more tame street manners of the Eaton.
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Project Family Values Build Thread Vehicles/Projects: -1971 C10 SWB Fleetside! Gathering parts now, will begin frame-off resto soon... Pleasure in the job puts perfection in the work. -Aristotle |
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#18 |
Senior Member
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Location: Tucson, AZ USA
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Re: Which brand of posi
I put an Auburn posi on the 3.73 12 Bolt rear in my '67 K/10 Suburban around 1995. Sub was rigged with a 454 BBC/TH350/NP205/ on 33X12.50X15 meats.
In late 1998, it had an engine fire, and I towed it home. It sat until 2012, when I blew up the factory 12-Bolt Eaton posi under my '71 GMC Jimmy. So my drinking buddy and I cannibalized the Auburn posi 12-Bolt off the Sub and fit it on the Jimmy. Yes, there were spring perch issues. The shorter [width-wise] '67 Rear went on under the '71 OK, but we could not get the narrower-width springs to stretch out to mate up to the '71's Rear. The Sub's Auburn posi rearend still works great on the GMC, until I can get the factory Eaton Rearend rebuilt and back under the Jimmy. If anything the narrower stance gives the Jimmy an even tighter turning circle. The first step to the Suburban Rebuild Project, will be to rebuild the Eaton posi. The '68 C/10 Stepside, L6 292/SM465/12-Bolt 3.73 w/Eaton posi has been running good for 34 years. ![]()
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Every 25 years I like to rebuild that 292, whether it needs it or not. Last edited by '68OrangeSunshine; 10-27-2019 at 09:57 PM. |
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#19 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,717
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Re: Which brand of posi
The OEM clutches were steel.
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44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
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#20 |
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Re: Which brand of posi
Keep in mind the OEM installed Eaton was the G80 Gov-Loc, which in all reality is complete junk. It's a centrifugal weight activated locker. They have tendencies to be inconsistent, noisy, and usually they unlock them selves when turning to one side vs. the other. They're also very weak, That 496 would make mince meat of them rather quickly. They aren't rebuildable.
Now, the Eaton LSD is an absolutely wonderful unit. They're super consistent, operate quietly, and are very tough. Also, they can be upgraded. in standard form, they come with 400 lb. preload springs and carbon clutches, but can be upgraded to 800 lb springs and Kevlar clutch material. They're also rebuildable. If you wear it out, send it back in the have the clutches and preload springs replaced. I personally have never dealt with the Tru-Trac, but I've never heard anything negative. I do know they're more preferred in road racing than dragstrip use. The Auburn unit is a good unit, but isn't rebuildable or upgradable. Also, if you're interested in better highway manners, a 3.42 gear is also a good option so you don't lose that low end grunt.
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#21 | |
Senior Member
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Location: Falls City, Nebraska "100 Miles From Nowhere"
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Re: Which brand of posi
Quote:
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" ![]() "Be American, Buy American" ![]() |
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#22 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,717
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Re: Which brand of posi
The G80 was only the Gov-Lok after 1973? Before that it was the standard Eaton posi as mentioned above.
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44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
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#23 |
Registered User
Join Date: Dec 2017
Location: East Windsor Ct
Posts: 27
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Re: Which brand of posi
Auburn is good but not rebuildable. The cone style clutch wears into the case making it a throw away. Takes years though.
True trac is very positive, sometimes noisy and sometimes a bit clunky Eaton is rebuildable and perfect for street use. My first choice. Yukon, yes, China. That said, I've built many rears at my shop and used many of these with no trouble. Never had a failure and the ring mount surface is always spot on as far as runout. I have one in my (Twin turbo truck). Don't lose sight of the fact that these trucks don't have any weight in the rear and you will be breaking the tires loose long before you generate enough torque to do damage. |
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#24 |
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Re: Which brand of posi
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#25 |
Senior Member
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Location: Pampa, Texas
Posts: 1,554
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Re: Which brand of posi
Tru-Trac for the win.... all day long.
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