From jgwolford at aol.com  Thu May 16 11:27:00 2024
From: jgwolford at aol.com (James Wolford)
Date: Thu, 16 May 2024 17:27:00 +0000 (UTC)
Subject: [Oletrucks] Task Force Differentials
References: <28915320.482169.1715880420679.ref@mail.yahoo.com>
Message-ID: <28915320.482169.1715880420679@mail.yahoo.com>

Hello all,
I have a 1957 Chevrolet 3100 pickup.? It currently has an open rear end and I believe the gears are 390 or the same as the sedan.? I am wondering about replacing the center section with a posi unit and was wondering if a 8.5 would work?
Thanks,
Jim W.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/oletrucks/attachments/20240516/1376068e/attachment.htm>

From miq at bigllama.com  Thu May 23 08:21:12 2024
From: miq at bigllama.com (MIQ MILLMAN)
Date: Thu, 23 May 2024 07:21:12 -0700
Subject: [Oletrucks] Task Force Differentials
In-Reply-To: <28915320.482169.1715880420679@mail.yahoo.com>
References: <28915320.482169.1715880420679.ref@mail.yahoo.com>
 <28915320.482169.1715880420679@mail.yahoo.com>
Message-ID: <CAASF5jEojRBQvTjvYPSRsHZGCypORgR_gKR37893bdeC5C9VoQ@mail.gmail.com>

Sorry for the late reply James.  I had to go through my paper archives from
when I modded my '57 3200.

Stock is 3.90:1 or 4:11:1 -- it depended on which transmission was
originally in the truck.

8.5" 10 bolts from '73 - '87 (Square Body) should fit.

I actually went a different route:  I put in a 1989 Camaro Z28 rear end,
that had both a posi-trac and disc brakes--this was a Borg Warner 9-bolt
with a 3:27:1 ratio-- this is also a smaller ring gear, 7.75, but was more
than adequate with my fuelie head/fenton headered/HEI 235 hotrod engine at
the time, especially since I also retained the 4 speed with granny 1st
gear..  I fixed the slight change in width by changing the offset on the
wheels I used.

In the drag world, the 9 bolt is sometimes considered to be a much superior
choice to the 10 bolt.  IF you go that route, make sure to get the 11 tooth
pinion/ 41 tooth ring if you go for the 3:73:1--it's much stronger than the
10 tooth pinion/37 tooth ring.


   --Miq



On Thu, May 16, 2024 at 11:20?AM James Wolford <jgwolford at aol.com> wrote:

> Hello all,
>
> I have a 1957 Chevrolet 3100 pickup.  It currently has an open rear end
> and I believe the gears are 390 or the same as the sedan.  I am wondering
> about replacing the center section with a posi unit and was wondering if a
> 8.5 would work?
>
> Thanks,
>
> Jim W.
> _______________________________________________
>
> Oletrucks at autox.team.net
> Donate: http://www.team.net/donate.html
> Suggested annual donation  $11.47
> Archive: http://www.team.net/pipermail/oletrucks
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/oletrucks/miq at bigllama.com
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/oletrucks/attachments/20240523/9953694e/attachment.htm>