04-09-2012, 06:14 PM | #1 |
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Location: Plano, TX
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12 bolt rearend
Looking at upgrading my 12 bolt rearend (1972 C/10). Looking at getting the Trutrac with 3.42 gears, also thinking about upgrading to rear disc brakes as well. Currently have 3.08 gears with drum brakes. Any ideas on the brakes, and thoughts/feedback on the gears and Trutrac.
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04-09-2012, 08:15 PM | #2 | |
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Re: 12 bolt rearend
Quote:
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John Paap Ole Greenie Hagerstown, MD My Mistress 70 CST Short/Step LS 5.3/4L65E New motor install Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=667773 |
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04-09-2012, 08:53 PM | #3 |
Its a Truck Thing......
Join Date: Dec 2004
Location: Sierra Vista, Arizona
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Re: 12 bolt rearend
Just put in 3.42 in my 12 bolt, also did the camaro calipers, works well so far.
http://67-72chevytrucks.com/vboard/s...d.php?t=518599 Smitty
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71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 69 C30 Former Motor Home, Flat Bed time 70 G20 Red-E-Kamp Conversion "I'm your Boogy Van" |
04-09-2012, 08:56 PM | #4 | |
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Re: 12 bolt rearend
Quote:
http://www.summitracing.com/search/B...c&autoview=SKU
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Lifes journey is not to arrive at the gate well preserved, it is to slide in sideways all used up and wore out yelling.....God what'a ride! Where patience fails, force prevails Stapp's Ironical Paradox "The universal aptitude for ineptitude makes any human accomplishment an incredible miracle." |
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04-09-2012, 09:32 PM | #5 |
motor exploder
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Location: Pittsburgh, PA
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Re: 12 bolt rearend
I have a Truetrac, 3.73's, Moser axles and Moser diff cover/brace in my 12 bolt also. Camaro calipers/Impala SS drilled & slotted rotors. I haven't driven it yet with the Truetrac, but when I was doing my shopping, everything I heard and read about the Truetrac was in line with what I needed. Try doing some searching on Team Chevelle (www.chevelles.com), a lot of those guys run the Truetrac in their car 12 bolts.
I will say that I have run the Auburn HP Series LSD in another truck I had and it performed well also. And what good would a post be without pics???
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Adam 1969 Chevy CST/10 stepside, DART Big M/TREMEC Magnum Extreme/3.73's w/Detroit Truetrac 1965 Chevy Bel Air Wagon (daily driver), 327/TH350,10 bolt w/3.08's 1961 Chevy Bel Air Sport Coupe, ZZ454/M21/9" rear w/3.50's & Detroit Truetrac 2005 GMC 1500 ccsb 2wd, 6.0L/4L65e/3.73 G80 2006 GMC 2500HD ccsb 4x4, DMax LBZ/Allison 6spd/4.56's w/Detroit TrueTrac Use the SEARCH function on this forum - it is your friend!! |
04-09-2012, 09:36 PM | #6 | |
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Re: 12 bolt rearend
Quote:
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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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04-09-2012, 09:41 PM | #7 |
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Re: 12 bolt rearend
I've read and researched tons of stuff on diffs and I agree, a 4L60E or 700R4 with a 3:42 gear with Tru-Trac is a great combo for all around use.
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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 |
04-09-2012, 10:01 PM | #8 |
motor exploder
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Re: 12 bolt rearend
The two allen head studs on each side of the 'Moser' logo in the pic above go all the way into the gear case and adjust up against the bearing caps on each side of the differential. They are supposed to stabilize the caps and keep them from 'walking' or moving around under load.
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Adam 1969 Chevy CST/10 stepside, DART Big M/TREMEC Magnum Extreme/3.73's w/Detroit Truetrac 1965 Chevy Bel Air Wagon (daily driver), 327/TH350,10 bolt w/3.08's 1961 Chevy Bel Air Sport Coupe, ZZ454/M21/9" rear w/3.50's & Detroit Truetrac 2005 GMC 1500 ccsb 2wd, 6.0L/4L65e/3.73 G80 2006 GMC 2500HD ccsb 4x4, DMax LBZ/Allison 6spd/4.56's w/Detroit TrueTrac Use the SEARCH function on this forum - it is your friend!! |
04-09-2012, 10:10 PM | #9 |
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Location: Oregon City, Oregon
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Re: 12 bolt rearend
There is a member on here that makes the brackets to bolt the Camaro and Cadillac calipers onto the 12 bolt. That's on my list for next winter.
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04-09-2012, 11:47 PM | #10 | |
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Re: 12 bolt rearend
Quote:
I used Captain's brackets for my rear brakes. Came out nice and they work great. I'm using an Eaton posi with 4:11s and a 700r4. I wouldn't change a thing.
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'68 C-10 SWB 383 Stroker (Sold 3/2/2013) '87 R2500 LWB 454 TBI converted to Carb Last edited by AusTx68; 04-09-2012 at 11:54 PM. |
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04-10-2012, 07:02 AM | #11 |
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Location: Smyrna, Ga
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Re: 12 bolt rearend
I am currently working on a similar project.
12 bolt with Eaton TruTrac and 4.10's. Using Cadillac D-52 calipers, Astro Van Rotors, and Captain Fabs brackets. I got the gears shimmed correctly, just need to clean it for final assembly and install it. |
04-10-2012, 08:45 AM | #12 |
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Re: 12 bolt rearend
I have been running 82 camaro calipers on the rear for a few years. They perform well but they do turn the emergency brake into a parking brake. To get mine to hold at a safety check beforee I shift into drive, I need to depress the pedal then pull the lever handle as much as I can get. I can just pass the test.
The foot parking brake may apply a little more pull. How did others fare on this? It is kind of a toss to me on disc on rear. My 2006 WT 4wd has drums. My former 2002 Z71 4wd had disc. |
04-10-2012, 09:48 AM | #13 |
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Re: 12 bolt rearend
Not to pirate the thread but what year on those Astro van rotors?
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04-10-2012, 01:03 PM | #14 | |
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Re: 12 bolt rearend
Quote:
For anyone looking for these rotors, Summit currently has a set of Astro van drilled and slotted rotors on clearance for $50 each. I almost bought them, but then i would have to change the fronts to drilled and slotted too. |
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04-10-2012, 01:34 PM | #15 |
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Re: 12 bolt rearend
Thanks for the ideas and feedback. Anyone know of a complete disc brake kit that works on the truck 12 bolt. By the way I have a TH350, and thought that 3.73 in the rear would be to low for me. What do you think about the change from 3.08 to 3.42, will it be a noticeable jump?
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04-10-2012, 02:07 PM | #16 |
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Re: 12 bolt rearend
This is a copy of an email from the guy i bought my posi from.
"Jason- We ship to Canada daily. Here is what we can do for you: $450 - GM 12-Bolt Truck Eaton Posi Unit - 30 Spline $135 - GM 12-Bolt Truck Ring & Pinion (3.73 Ratio) $65 - GM 12-Bolt Truck Master Bearing/Installation Kit ------------------------------------------------------------------------------------- $100 - SHIPPING via UPS Worldwide Standard (3-5 Days) ------------------------------------------------------------------------------------- $750 - TOTAL You would have a flat $10 brokerage fee and the taxes would run $20-$30. Let me know if you have any other questions. Thanks, BRYDON 641-751-8060 staticz2229@gmail.com" I think shipping to the US was free. Great product for a great price. I found his stuff on ebay.
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69 c10 lwb |
04-11-2012, 02:36 AM | #17 |
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Re: 12 bolt rearend
Tru-trac is a nice traction device for the street but if Im not mistaken its only offered in 12-bolt truck in the 3.73-up carrier. If you want 3.42 gears you gonna have to use a clutch or cone type. Too bad, I wanted a tru-trac but 3.73s are too tall for my th400 and 28" tires
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04-11-2012, 05:54 PM | #18 |
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Re: 12 bolt rearend
Well that sucks, I came across Moser's website, and they offer the 3.42 gear set/trutrac for their 12 bolt. Since theirs is a custom rearend explains why they are probably able to offer it.
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04-11-2012, 09:23 PM | #19 |
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Re: 12 bolt rearend
Just had Moser build this one....true trac....3.73.....33 spline.....Grand sport brakes...kore 3 brackets....
Here's link to board member's kit for truck c5 kit.....I bought one ...but then changed to big ford bearing rear...sold mine...nice kit..... http://67-72chevytrucks.com/vboard/s...d.php?t=415021 here's pic of kit also...........jim
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Build thread at http://67-72chevytrucks.com/vboard/s...d.php?t=475791 |
04-11-2012, 09:45 PM | #20 | |
Its a Truck Thing......
Join Date: Dec 2004
Location: Sierra Vista, Arizona
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Re: 12 bolt rearend
Quote:
The camaro calipers work well on the 12 bolts. Smitty
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71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 69 C30 Former Motor Home, Flat Bed time 70 G20 Red-E-Kamp Conversion "I'm your Boogy Van" |
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04-11-2012, 10:57 PM | #21 |
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Re: 12 bolt rearend
Jp that looks awesome, thanks for the info.
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