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 08-01-2010, 10:20 PM   #1
thepunisher
Registered User
 
thepunisher's Avatar
 
Join Date: Aug 2009
Location: Rochester, MN
Posts: 201
Posi Swap

There is a posi rear differential for sale near me. The ad says it's from a '72 chevy truck. My truck doesn't have the a posi differential. Is it possible to just swap out the internals into my differential or are the housings different? I am going to have the differential rebuilt by a local shop eventually and would like do the posi conversion as well. I'd also like to not have to swap the differentials I've just rebuilt the brakes, and painted it.
__________________
Blayne
thepunisher is offline   Reply With Quote
Old 08-02-2010, 12:47 AM   #2
nightmare
Senior Member
 
nightmare's Avatar
 
Join Date: May 2002
Location: Hammond, WI
Posts: 1,804
Re: Posi Swap

housings are the same, and it should just bolt right in.
__________________
Mike

2001 Dakota R/T - Silver CC - 1 of 1671 •360 w/46RE •392 limited slip
1972 Chevy Suburban - Turquoise/Black
1969 Chevy C/10 - Blue LWB •350 w/ 700R4 •3.73 posi •PS PB A/C - SOLD

Using your turn signal is not "giving information to the enemy"

67-72 FAQ

Quote:
Originally Posted by GMCMAX View Post
My lugnuts require more torque than your honda makes!
nightmare is offline   Reply With Quote
Old 08-02-2010, 11:18 AM   #3
thepunisher
Registered User
 
thepunisher's Avatar
 
Join Date: Aug 2009
Location: Rochester, MN
Posts: 201
Re: Posi Swap

Awesome, that's what I thought but figured I should check to make certain before I bought it.
__________________
Blayne
thepunisher is offline   Reply With Quote
Old 08-02-2010, 04:44 PM   #4
charx2
Registered User
 
charx2's Avatar
 
Join Date: Apr 2010
Location: Mobile, AL
Posts: 365
Re: Posi Swap

Don't you still have to measure the backlash and all?
__________________
-----------------------------------------
My 67 c10 Thread.
http://67-72chevytrucks.com/vboard/s...d.php?t=409192
charx2 is offline   Reply With Quote
Old 08-02-2010, 04:46 PM   #5
charx2
Registered User
 
charx2's Avatar
 
Join Date: Apr 2010
Location: Mobile, AL
Posts: 365
Re: Posi Swap

Opps, sorry thought you meant you were going to just pull the old and put it in your housing, lol. I jumped the gun on that one!
__________________
-----------------------------------------
My 67 c10 Thread.
http://67-72chevytrucks.com/vboard/s...d.php?t=409192
charx2 is offline   Reply With Quote
Old 08-02-2010, 05:12 PM   #6
cdowns
Senior Member
 
cdowns's Avatar
 
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
Re: Posi Swap

yes its not a matter of just ploping it in the typical measurements and clearances as per service manual should b followed to install and set the gears up
__________________
71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane

MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF

DONT BELIEVE EVERYTHING YOU THINK

TAKE MY ADVISE;I DON'T USE IT ANYWAY
cdowns is offline   Reply With Quote
Old 08-02-2010, 05:21 PM   #7
thepunisher
Registered User
 
thepunisher's Avatar
 
Join Date: Aug 2009
Location: Rochester, MN
Posts: 201
Re: Posi Swap

Just to clarify, it is possible to remove the posi unit from the donor differential, and properly install it into my housing? What about the ring and pinion? If my truck has a 3.43 gear and the donor has a 4.10 is it possible to use my 3.43 gear with the posi unit?
__________________
Blayne
thepunisher is offline   Reply With Quote
Old 08-02-2010, 06:32 PM   #8
cdowns
Senior Member
 
cdowns's Avatar
 
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
Re: Posi Swap

yes you can switch them you'll need new shims and crush sleeve etc.
__________________
71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane

MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF

DONT BELIEVE EVERYTHING YOU THINK

TAKE MY ADVISE;I DON'T USE IT ANYWAY
cdowns is offline   Reply With Quote
Old 08-02-2010, 07:36 PM   #9
LONGHAIR
just can't cover up my redneck
 
Join Date: May 2004
Location: Columbus OH
Posts: 11,414
Re: Posi Swap

If you currently have 3.42 gears and the Posi unit that you are looking at is made for 4.10s, you are out of luck.
The 3.42 gears will not work on a 4 series carrier. You would have to jump up to at least 3.73.
Either way you really need a Professional to do this install. It is very critical that it be done correctly....and it gets expensive when it's not done right.
__________________
You can review the site's rules here.



Quote:
Originally Posted by Longhorn Man View Post
As for reading directions...
The directions are nothing but another man's opinion.
Learn from the mistakes of others, you won't live long enough to make them all yourself...

Bad planning on your part does not necessarily constitute an instant emergency on my part....

The great thing about being a pessimist is that you are either pleasantly surprised or right.
LONGHAIR is offline   Reply With Quote
Old 08-03-2010, 09:25 AM   #10
thepunisher
Registered User
 
thepunisher's Avatar
 
Join Date: Aug 2009
Location: Rochester, MN
Posts: 201
Re: Posi Swap

I am definitely going to have a local shop do the work. I have already spoken to them about doing a rebuild. Hopefully it will be a rebuild with a posi swap!
__________________
Blayne
thepunisher 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 01:20 PM.


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