Official Rear end ratios thread - 1928 - 1956 Mopar

[oldasdirt]

I have spent several hours looking through threads of changing rear ends, and ratios being listed for newer rear ends.  I also see on the truck forum there are a few great threads listing the various years and rear end ratios available for various years and models of trucks.

 

I can not seem to find on the forum or on the internet anywhere that has the various rear end ratios for the Mopar Car Family.

 

Those being Plymouth, Chrysler, Dodge & Desoto.

 

Does anyone know of any such resource ?

 

If there isn't I thought I would start a thread to attempt to cover them.

 

I do know in 1957 when Mopar introduced the 8 3/4" rear end the breath of ratios ballooned. and you could get from 2:76 to 5:57 in 12 different

ratios and those are covered nicely on this site.

 

http://bionicdodge.com/Download/Mopar_8_3_4_Rear_End_Guide.PDF

 

 

However I was thinking of trying to put together the resource for the pre-1957 rear end ratios.

 

I have a few manuals so I will attempt to list those and I am hoping others with chime in.

Edited February 26, 2016 by oldasdirt

[desoto1939]

I do know that my 39 Desoto has the 4.11 rear and this was a factory rear that is still in the car.

 

Rich HArtung

[oldasdirt]

1941 Plymouth -  taken from the Detroit - Chrysler Corporation Plymouth Passenger cars part list

 

3:73 (economy) 664941

3:91 (coupes) 664687

4:1 (all sedans  utility and delivery sedans and Suburban)  664392

4:1 (passenger coupe) 664392

4:3 (export & convertible coupe) 664688

4:56 (special ratio) 695539

4:78 (export, limo - 18" wheels) 664689

4:89 (limo) 664604

[oldasdirt]

1953-54 - Chrysler Corporation  Parts list 

c56, c58, c59, c60

d43, d44 , d46, d47, d48, d49, d50, d51, d52, d53

s16, s18, s19, s19, s20

p24, p25

 

3:36 s16 1483887,  with t.c 1485078

3:54 overdrive p24-d43  1489174, 1489229,  s18 c60 1489229, 1404482, 1330696, 1330696

3:73 overdrive 1489175, s20 c62 1489250, s16 1405926. 1330710

3:9 overdrive 148189, exc t.c  1480189, 1489223

3:91 8 sedan 1330710

4:10 export sp24-25  1489177. 8 sed. 1330718

4:3 8 sed. 1339728

4:3 special p24-d43  1489178

[desoto1939]

1939 Desoto Differential Information

 

4.1 to 1   All except 7 pass sedan and limo  wo overdrive  663442

4.3 to 1   all except 7 pass, sedan and limo with overdrive  663456

4.3 to    7 pass. sedan and limo  wo overdrive 666880

4.56 to 1   7 -pass sedan and limo with overdrive  697311

4.78 to 1  Export to La Paz Bolivia all except 7 pass sedan and limo  663649

4.89 to 1  Export to La Paz Bolivia  7 pass sedan and limo  670577

 

Rich Hartung  found this in my 39 Desoto Parts book

Desoto1939@aol.com

[knuckleharley]

I do know that my 39 Desoto has the 4.11 rear and this was a factory rear that is still in the car.

 

Rich HArtung

My 42 Dodge coupe came stock from the factory with a 4:11 rear or a 4:4something rear. I did manage to find a buy a NOS 3:73 ring and pinion for it,though. I'm guessing the 3:73 option was popular in the flat mid-west where there were lots of miles between gas stations.

[Frank Elder]

My 42 Dodge coupe came stock from the factory with a 4:11 rear or a 4:4something rear. I did manage to find a buy a NOS 3:73 ring and pinion for it,though. I'm guessing the 3:73 option was popular in the flat mid-west where there were lots of miles between gas stations.

A D-22 bizzy coupe actually came with 3.73 to 1 according to the manual. with or without fd.

all sedans with fd....3.9 to 1 without fd.....4.1 to 1.

club coupe with fd or without 3.9 to 1. 

vert with fd 3.9 to 1  without fd...4.1 to 1

7-passenger sedan with or without fd 4.3 to 1.

 

 

If you guys change your gear sets you must also put the correct speedo gear in the tranny to read correctly.

[knuckleharley]

A D-22 bizzy coupe actually came with 3.73 to 1 according to the manual. with or without fd.

all sedans with fd....3.9 to 1 without fd.....4.1 to 1.

club coupe with fd or without 3.9 to 1. 

vert with fd 3.9 to 1  without fd...4.1 to 1

7-passenger sedan with or without fd 4.3 to 1.

 

 

If you guys change your gear sets you must also put the correct speedo gear in the tranny to read correctly.

Thanks for the updates. Mine is a business coupe with fluid drive,and when I started researching this stuff after buying the car a few years ago,I was told or read all the 42's came with either 4.1 or 4.3 rear. Otherwise I never would have spent the big bucks for a 3:73 ring and pinion.

 

I guess the good news is I can always sell it to someone else if it won't work in my 33 Dodge sedan. Does anyone know if rear parts in the 33 and 42 are interchangeable?

[austinsailor]

From my "MOPAR 1954 and prior year Passenger csr parts list" Apr 1, 1955, (1946 - 1954) this list of differential applications.  If the resolution isn't good enough, message me and I'll email you a higher resolution version.

 

One page on this post, second on next. Too big for both on one post.

 

[austinsailor]

page 2 of diff list, 1946 - 1954.