Click on image for the lowdown. 
====
| | |
7 members (Gray_Ghost, Rusty Heaps, Brian Moore, 55shaker, Otto Skorzeny, Hotrod Lincoln, 1 invisible),
85
guests, and
2
robots. | | Key: Admin,
Global Mod,
Mod | | | Forums66 Topics128,028 Posts1,055,414 Members48,422 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Jul 2017 Posts: 45 'Bolter | | 'Bolter Joined: Jul 2017 Posts: 45 | Casting on the diff is 3707340 or 3707343. Located on pass side.
The other code is a circle(like a zero with something in the center) and D1
This is in a 1955 series 2 3100.
Question 2: Why is there nothing mentioned about rear differentials in the 1955 factory assembly manual?
Thanks in advance
Jim
Jim
1955 Chevy series 2
6 cylinder, 3 on the tree
Short bed, step side
| | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | Casting numbers are different than part numbers 3707340 fits 1955-1962 Chevy. It is a GM HO-35. What are you trying to figure out. If you are trying to fix your third member you need a maintenance manual instead of an assembly manual. Assembly manuals usually cover body parts and complete components. | | | | | Joined: Jul 2017 Posts: 45 'Bolter | | 'Bolter Joined: Jul 2017 Posts: 45 | Thanks for the info crenwelge. First (only) helpful information I've gotten on these numbers. Can I ask where you found decoding info? I've looked all over. Well obviously not all over.
I want to change the ring and pinion from 3.90 to 3.08. I haven't seen anything lower than 3.38. That'll be ok.
Guess I've got to get it apart to see what's in it.
I'll also look into getting the maintenance manual.
Thanks again
Jim
Jim
1955 Chevy series 2
6 cylinder, 3 on the tree
Short bed, step side
| | | | | Joined: Mar 2014 Posts: 4,479 Moderator, Electrical Bay | | Moderator, Electrical Bay Joined: Mar 2014 Posts: 4,479 | As I recall you can't get a 3.08 for that one, Jim. 3.38 is available, but I believe that's as far as you can go. Good luck. A 3.08 12 bolt rear was available in the 1969 pickup and the width is good for these trucks.
~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
| | | | | Joined: Mar 2014 Posts: 4,479 Moderator, Electrical Bay | | Moderator, Electrical Bay Joined: Mar 2014 Posts: 4,479 | Forgot to mention, if you want a wealth of information about your truck, use the GM Heritage pages. Here's the 211 pages for yours: https://www.gmheritagecenter.com/do...ucks/1955-Chevrolet-Truck-2nd-Series.pdf
Last edited by Jon G; 09/20/2021 2:58 PM.
~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
| | | | | Joined: Mar 2014 Posts: 4,479 Moderator, Electrical Bay | | Moderator, Electrical Bay Joined: Mar 2014 Posts: 4,479 |
~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
| | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | Along with being in the trucking business since 1964 and growing up in the gasoline business I was a licensed salvage dealer for many years. A book called the Hollander is what salvage dealers use to determine what interchanges and a lot of it is just remembering what worked last time you tried it. I will be 78 in a few weeks and there are not many of my generation left that still do things the old fashioned way. I think the 3. 90 and 3.38 fit in the same GM corporate housing. They call it a H033 at 3.90 and H0335 at 3.38. The 3.38 was offered behind automatics. The 3.08 was a Spicer which is a totally different animal. I still run a dozen trucks, have a couple of gas stations, but I dropped my salvage dealer's license a few years ago. https://photos.app.goo.gl/u7JHgEqaPRRbUCZE9 | | |
|
|
