| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,017 Posts1,055,338 Members48,419 | | 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: Sep 2007 Posts: 84 'Bolter | | 'Bolter Joined: Sep 2007 Posts: 84 | Is the 1955 1st series differential the same as the 1955 2nd series? I'm thinking about swapping my torque tube rear for a complete 1955 open drive rearend but I want to make sure I'm getting the right axle.
Thanks
1953 3100 | 1958 3/4-ton NAPCO
| | | | | Joined: Jan 2001 Posts: 1,420 ODSS President | | ODSS President Joined: Jan 2001 Posts: 1,420 | tt is 4.10, open is 3.90. All you need to do is swap the differential itself, the axles are the same on both units. for instance I have been using '49 axles for 10 years with a '57 3.90 differential. I do use an overdrive with this giving me a final drive of 2.73; that is .70 X 3.90 = 2.73
~ Cosmo
1949 Chevy Half Ton
Rocinante, like Don Quixote, he is awkward, past his prime, and engaged in a task beyond his capacities.
"...my good horse Rocinante, mine eternal and inseparable companion in all my journeys and courses." ...Don Quixote, Cervantes
"If you come to a fork in the road, take it."...Yogi Berra
"Rudeness is the weak man's imitation of strength." ...Eric Hoffer
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 |
The ratios of standard 1955-1st and 1955-2nd 1/2 ton trucks are the same, 3.90:1 (unless you have the 55-2nd RPO overdrive rear end: it would have 4.11:1 ratio).
Also, 1955-1st 1/2 ton trucks had an open driveshaft (1954 was the last year for the 1/2 ton torque tube).
Tim
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 |
I think graydon might be asking about rear-end-width (drum-to-drum) and maybe spring mounting.
1955-1st compared to 1955-2nd
| | | | | Joined: Sep 2006 Posts: 2,393 Shop Shark | | Shop Shark Joined: Sep 2006 Posts: 2,393 |
Drew
| | |
|
|
| |
