VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Rearend I.D

As you regulars over on Chevy talk know I have recently picked up a rearend, that the guy I bought it from and I seem to agree that its a 3.55:1 ratio. Stamped in the rearend is a series of numbers(M S 602) Im not saying that the guy who answered me on Chevytalk was wrong ,im just wantin to get a second opinion. Was told this rear was out of a 54.If that is true and if its not a 3.55 rear I am still in luck beacause the normal(non powerglide) ratio was 3.70:1 CORRECT??????.....thanks for the input....Chris

Number M S 602 breaks down as follows:

M = Model Year Desigination for 1954

S = Chevrolet Gear & Axle build location

602 = sixth month, second day or June 2, 1954

That combination was identified as Axle NO. 3708810 and was released for usage on 1500 - 2100 - 2400 series vehicles as RPO 313. I don't own a parts book that covers that particular year, but that may not be of any help since Production Released Part numbers are not always the same as Service part numbers. However, if someone can tell you what PRO 313 is, you should learn the axle ratio from that. Otherwise, you can count the ratio.

Update: Identified RPO 313 as the designation for Powerglide Transmission.

SWEET!!!! THAT MEANS IT IS A 3.55:1, AWESOME....THANKS A MILLION.....CHRIS

hi i'm new here.i am currently restoreing a 1949 half ton.my truck is missing the rearend all together.any ideas on what would fit?i am able to move spring pads.thanks boomer

If the half tonners have open driveshafts, you can help yourself in a good Chevy pickup junkyard. Just try to know what you´re buying. You can rotate the driveshaft and one side of the diff to check the axle ratio.
Mahar