help me figure out a posi for my 67

[wp silverado]

ive got a 67 c-10 im looking to get a posi for. ive done some looking around and researching but im kind of confused on what to buy. ive been told there are a few different carriers in the 67-72 trucks and im kinda lost and dont want to get the wrong part. so ask whatever questions you need to ask me and lets figure out what i need.

[junkman]

If you are wanting to reuse your gears you will need to make sure you buy a carrier that matches them, 2,3,4 series. From there it's your choice. I am a fan of the stock style eatons. They work, can pick them up used pretty reasonable, and are rebuildable.

[wp silverado]

i am looking to reuse my 4.11's and i want something i can rip on HARD without having to worry about leaving me stranded. how can i tell what series carrier i have?

[kgt]

power trax...installs into the factory carrier, installed mine in a hour or so, it lives behind a dart headed 468, roller cam, 3500 stall and 3.73s, seems strong enough....

[rogergodding]

Originally Posted by kgt

power trax...installs into the factory carrier, installed mine in a hour or so, it lives behind a dart headed 468, roller cam, 3500 stall and 3.73s, seems strong enough....

I got a quote today for rebuilding my rear end today with an eaton posi at $1000.00. Is it really all that difficult?

[kgt]

Originally Posted by rogergodding

I got a quote today for rebuilding my rear end today with an eaton posi at $1000.00. Is it really all that difficult?

up here a grand is a smokin deal..it isn't a easy job and some of the tools are not something that everyone has, or the knowledge for that matter...a grand sounds more than fair...

[rogergodding]

Originally Posted by kgt

up here a grand is a smokin deal..it isn't a easy job and some of the tools are not something that everyone has, or the knowledge for that matter...a grand sounds more than fair...

wasn't trying to hi-jack thread, so I sent you a pm....

[kgt]

Originally Posted by rogergodding

wasn't trying to hi-jack thread, so I sent you a pm....

Pm sent back to you!!...sorry to the o.p.

[JimmyFloyd]

what rear do you have now?

[wp silverado]

thats my perdiciment, im a mechanic by trade but dont know much about these specific rears. all i know for sure is its a 12 bolt with 4.11's and 5 lug axles

[rogergodding]

For what it's worth, I am looking into the powertrax unit that kgt mentioned!

[67/72junkie]

If it's a street truck with dana 40 standard and eaton style or other it will live with a huge high hp engine with some tire spin.If you Drag race it hard with serious hp and big slicks it will fail at some point.I sold 69 swb with 450 hp 400 small block to my friend.I drove it on the street with eaton and 373 for years with no problem . he put a 4500 stall and transbrake in it with big slicks and tore it out in less than 3 months. after 2 more all new rear ends broke in less than a years time he got a dana 60 from a 3/4 ton and had the tubes cut off.had clip eliminators welded on ordered after market axels with the six lug pattern.It has a 468 with remorrison aluminum heads and runs 6.50 in the 1/8th mile on gas. has gone 900 ft on rear tires at wheelie contest.We will be at pinks all out the end of april at charolette if anybody wants to see a 3500lb all steel 69 swb go down the track on the rear tires.made it to the sweet 16 last time and had converter problems .It has not had a rearend failure of anykind in over 10 years with the dana 60.

[wp silverado]

so how do i tell what i have?

[67/72junkie]

67/72 1/2 tons come with dana 40 standard.Has 12 bolts in rearend cover.If factory limited slip "posi" it will be eaton posi unit.There are several others auburn, etc but they are after market.they are good street rearends stock but if I had to spend alot of money in 1 I personally would use the dana 60 and be almost bullet proof.I have 1 out of a 72 3/4 with coil springs 4.10 posi that I am going to do the same as my buddy's truck.C clip eliminators,5 lug aftermarket axels,factory 5 lug drum brake stuff off parts truck.I am also using the trailing arms from the 3/4 ton because it comes factory with a 1/4" plate welded all the way down the top of them to stiffen them and keep them from separating.It is going to be a pro street truck so I am retaining the factory posi so I can drive on the highway.If it was and all out drag truck I would use a spool.

[Fast Freddy]

Thanks a ton, great info for sure. I should have the hot rod on the road in a few months but it will be a driver and but a bunch of "Punch" -- You guy are a heap of help
Thanks

[Fast Freddy]

Along the same lines here, I have a 68 C10 and would like to update the rear end. Is there not a "whole" rear end out three out of a later model truck that could be installed with limited slip, better handling etc?
Thanks

[wp silverado]

im still lost... i know its a dana 40 12 bolt. my question is how do i put a posi in it and retain my 4.11's, how do i tell what series carier i have, please help

[cdowns]

Originally Posted by wp silverado

im still lost... i know its a dana 40 12 bolt. my question is how do i put a posi in it and retain my 4.11's, how do i tell what series carier i have, please help

easy way is to buy an read factory service manual

[kgt]

Originally Posted by wp silverado

im still lost... i know its a dana 40 12 bolt. my question is how do i put a posi in it and retain my 4.11's, how do i tell what series carier i have, please help

It seems that you have a 4 series carrier based on the info above.

[63chevyll]

i like the detroit Tru Track and eatons,

pretty good for the street

[67/72junkie]

If you have 4.11s now all you need to do is order a posi what ever brand you chose and specify that you have 4.11s and a dana 40 standard.Take your truck to a reputable shop that does rearend work and not just any mechanic to have the unit installed.If they do good work he will recommend that you replace all bearings and seals while they are installing the unit.They should always replace pinion bearings and seal along with new carrier bearings on the new posi.It is not necessary but you should go ahead and replace axle bearings and seals while you're at it.They will have to pull the drums and slide the axles back anyway so spend the few extra bucks to make everything new at one time and save extra labor on replacing axle bearings later.

[kgt]

Some info ...

One of the most important things to consider, if you are looking at a swap meet or salvage yard, is the type of 12-bolt rearend you do find. GM made three different types of 12-bolt Positraction carriers. Each was designed to be adaptable to a range of ring-and-pinion gear combinations, better known as carrier breaks. Interchanging between these carrier breaks is possible; however, to keep costs down, it is important that you do your homework before you buy one.

Probably the easiest 12-bolt differentials to find are the type 2 units. These are found primarily in standard-performance Chevrolet passenger cars. Type 2 ratios were somewhere between 2.29:1 and 2.73:1. These type 2 carriers were not intended for any performance applications, but are more for fuel economy or a lot of highway driving.

Type 2 original equipment ratios:

2.29:1 (32-tooth ring gear, 14-tooth pinion)
2.56:1 (41-tooth ring gear, 16-tooth pinion)
2.73:1 (41-tooth gear, 15-tooth pinion)
Because of the width of the flange where the ring gear mounts, you cannot use larger differential ratios in a type 2 rearend without changing the carrier. A larger ring gear will bolt onto the type 2 carriers, but you will not be able to get the proper spacing.

Type 3 carriers are thicker, and are designed for use with original gear ratios ranging from 2.76:1 up to 3.73:1.

Type 3 original equipment ratios:

3.07:1 (43-tooth ring, 14-tooth pinion)
3.31:1 (43-tooth ring, 13-tooth pinion)
3.55:1 (39-tooth ring, 11-tooth pinion)
3.73:1 (41-tooth ring, 11-tooth pinion)
Type 4 gear carriers are the thickest; these units were available in several ratios, all 3.73:1 or larger:

4.10:1 (41-tooth ring gear, 10-tooth pinion)
4.56:1 (41-tooth ring gear, 9-tooth pinion)
4.88:1 (39-tooth gear, 8-tooth pinion)
Additional larger type 4 gears are available from many aftermarket suppliers.

The type 3 and 4 carriers are stronger than the type 2, because additional reinforcement webbing was built into the rear case. This helped to alleviate some of the higher torque stresses when used on the larger ratio combinations.

[kgt]

more info....

12-Bolt Truck Rear Info>>
You have 3.07 gears & a 3-Series Carrier which used OEM 3.40 & numerically lower gears.
4-Series Carriers used OEM 3.73 & numerically higher gears.
You need the Thick 3.73 gears for a 3-Series Carrier and a Master Install kit + Axle Bearings & Seals.
I've had good luck here>> http://completeoffroad.com/
3.73 >> http://completeoffroad.com/i-123019...ars-gm-12t.html
You can also check with >>
Tom's Differentials>> http://www.tomsdifferentials.com/
Randy's ring & Pinion>> http://www.ringpinion.com/#
DTS>> http://www.drivetrainspecialists.com/index.html

[wp silverado]

kgt thank you very much. but just to make sure, the fact that i have 4.11 gears means the only possible carrier that would work with them is the 4 series carrier/posi unit?

so i need to order a 4 series aftermarket posi

[big_al_71]

I went with an "Auburn" unit so far so good it has been there for two months..