The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-23-2008, 09:28 PM   #1
ChadBice
Registered User
 
Join Date: Jun 2002
Location: Sand Lake, MI
Posts: 45
10 Bolt v. 12 Bolt

I'm sure this topic has been covered a million times, but my poor searching techniques haven't been able to find an answer to my question.

I have a 1971, C10 with leaf springs and a 10 bolt rear end. The engine is a 350, slightly warmed. It currently has a TH400, but I'm debating changing it to a 700R4. With that in mind, is there any reason (aside from the fact that a 12 bolt is much more durable) that I should change the rear end if the one I have is good? Some people have said that the 10 bolt is too weak for my motor. Can that be true? That's what came from the factory. If I do change it, what can be used as a donor? Thanks!
__________________
Chad
'71 Chevy SWB
ChadBice is offline   Reply With Quote
Old 08-23-2008, 09:52 PM   #2
Gray Ghost
Senior Member
 
Gray Ghost's Avatar
 
Join Date: Sep 2004
Location: Terrell, TX
Posts: 1,967
Re: 10 Bolt v. 12 Bolt

I had a 10 bolt behind a 350 hp SS El Camino....it held fine for years. I doubt you'd have any trouble with it but you might have it checked anyway just in case. Personally I see no reason to change it if the gears are good.
__________________
Kelly
'05 GMC Sierra SLE Z71
Bone stock except for new bed rail caps.
Gray Ghost is offline   Reply With Quote
Old 08-23-2008, 10:02 PM   #3
Longhorn Man
its all about the +6 inches
 
Longhorn Man's Avatar
 
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
Re: 10 Bolt v. 12 Bolt

I'm wondering who went through the trouble of putting a weak axle in your truck.
They never came with 10 bolt rears
Longhorn Man is offline   Reply With Quote
Old 08-23-2008, 10:20 PM   #4
redhead69
fugedaboutit
 
redhead69's Avatar
 
Join Date: Mar 2005
Location: Gresham, OR
Posts: 832
Re: 10 Bolt v. 12 Bolt

Theres a few different 10 bolts.. some would hold up fine like the 8.5 and 8.2, but if you have the 7.2 or 7.5 ring gear Id be a little leary.
Heres a link to help you

http://www.maliburacing.com/rearend_guide.html
__________________
Currently truckless
redhead69 is offline   Reply With Quote
Old 08-23-2008, 10:22 PM   #5
msgross
Registered User
 
msgross's Avatar
 
Join Date: Jul 2006
Location: Central PA
Posts: 12,201
Re: 10 Bolt v. 12 Bolt

do you have a pic of the axle?
__________________
The Garage:
1968 K-10 SWB - "Project Money Pit"
1996 Z-71 - "huntin rig"
1969 C-10 LWB (SOLD) "Project flip that truck or else"
1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie"


My Garage Build "The 1,000 footer"
msgross is offline   Reply With Quote
Old 08-24-2008, 04:55 PM   #6
ChadBice
Registered User
 
Join Date: Jun 2002
Location: Sand Lake, MI
Posts: 45
Re: 10 Bolt v. 12 Bolt

Here's a photo of the rear end.
Attached Images
 
__________________
Chad
'71 Chevy SWB
ChadBice is offline   Reply With Quote
Old 08-24-2008, 04:57 PM   #7
msgross
Registered User
 
msgross's Avatar
 
Join Date: Jul 2006
Location: Central PA
Posts: 12,201
Re: 10 Bolt v. 12 Bolt

yep, basic chevy 10-bolt. Don't know the ring size though.

I say run it till it breaks... why fix what's working.

If you decide that you don't like the gearing then keep your eye out for a 12 bolt posi unit...may pay $300-400 for a decent one.

I sold an open 12 bolt for $50 cause I was tired of hauling it around.
__________________
The Garage:
1968 K-10 SWB - "Project Money Pit"
1996 Z-71 - "huntin rig"
1969 C-10 LWB (SOLD) "Project flip that truck or else"
1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie"


My Garage Build "The 1,000 footer"

Last edited by msgross; 08-24-2008 at 04:59 PM.
msgross is offline   Reply With Quote
Old 08-24-2008, 07:01 PM   #8
Mike C
Registered User
 
Mike C's Avatar
 
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,715
Re: 10 Bolt v. 12 Bolt

Looks like an 8.5. See the ears below the cover? Ring gear diameter is close enough to the 12 bolt to not make a difference. The pinion diameter is larger than the 12 truck (same as 12 car) The ring gear bolts are reverse threaded and larger in diameter than the 12 bolts, so that's a push. Only short coming is 28 spline axles if the rear is pre 88. Later model 8.5's are every bit equal to a 12 bolt truck.
__________________
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
Mike C is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 01:06 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com