Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics> 48 pontiac rear end
User Name
Password
lost password?   |   register now

Thread: 48 pontiac rear end Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
01-08-2013 01:44 PM
techinspector1 Be careful when using charts that list "rear end widths" and pay close attention to where the measurements were taken from. They might have measured from drum to drum or from axle stub to axle stub or from the centerline of the rear tires (track).

I suggested the Gen I Camaro after finding the TRACK of the '48 Pontiac and the TRACK of the Camaro and the fact that the Camaro is leaf-spring suspended, just as in your car. I'm not saying that the Camaro is the only choice out there. As was suggested, get all the measurements off your car, then take a tape measure to the various boneyards in your area and begin your search.

Also, if you need to tweak the track a little to use a taller or wider tire on the back of the car, wheels are manufactured with any range of backsets.
Wheel tech - Wheel offset clarified
01-07-2013 06:42 PM
455olds I would also like to add that if you are adding more power the stock brakes seriously need upgrading anyway, front and rear.
01-07-2013 06:28 PM
JeffE Thanks guys for your advise. Jeff
01-06-2013 08:18 PM
1971BB427 Jeffe, I'd be concerned about using the '54 and earlier GM enclosed driveline rearends in any V8 application. You would have to adapt the newer engine to an older trans that fit the enclosed driveline, or adapt a newer trans to the old enclosed driveline sytem.
Best to find a newer rearend that allows an open driveline, and not use your present setup. I would measure your spring perch centers, and the width of the rearend from drum surface to surface. You may most likely need new spring perches, so overall width is really the most important measurement. Then start looking around the wrecking yards to see what might interchange, and various bolt patterns. I'd guess your's is still 6 bolt, and you may have to either convert the front to match a 5 bolt patterrn, or use different bolt pattern for the rear.
An S10 rearend with 5 on 4.75" pattern often works well in these older Pontiacs width wise, and the 7.5" 10 bolt has been used behind V8's with good success.
Here's a rearend width chart for donor rearends:
Rear End Widths
Since you're going with a 700R4, you'll have overdrive, so try to find a S10 rearend (or whatever rearend) with a ratio around 3.50-3.73, as that will work best with the 700R4's low 1st gear, and overdrive.
01-06-2013 02:24 PM
techinspector1
Quote:
Originally Posted by JeffE View Post
I have a 48 Pontiac that I plan on street rodding by putting in a sbc 350 and 700r4, making it more of a highway cruiser. My question is has anybody done this and used the stock rear end ? How strong are these rear ends ?
What size ring gear are these ? Any info ?
Thanks
Look at it this way....the most powerful motor that was used by Pontiac in 1948 was rated at 220 lbs/ft of torque. If your motor will make that torque or less, then use the original diff. If you plan more power than that, then replace the diff with a later, stronger unit. I believe the original Pontiac diff was hung on leaf springs and had an open driveline. The rear track (centerline of the passenger side tire to the centerline of the driver's side tire) was 61.5", so take a tape measure and find a boneyard donor that has measurements close to that with leaf spring pads on the tubes. Brakes were internal-expanding shoe, hydraulic type, so any later model diff that has the spring pads and ~61.5" track should work. I might start off looking at Gen I Camaros.
01-06-2013 05:22 AM
JeffE
48 pontiac rear end

I have a 48 Pontiac that I plan on street rodding by putting in a sbc 350 and 700r4, making it more of a highway cruiser. My question is has anybody done this and used the stock rear end ? How strong are these rear ends ?
What size ring gear are these ? Any info ?
Thanks

Posting Rules
You may post new threads
You may 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


All times are GMT -6. The time now is 08:50 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.