1956 Rear End Casting Code

[Sheldon S.]

Can someone tell me the correct casting code for a early 56, ser. 282 Mine says 3707306 and thats what I seem to find in the archives but there is not a lot of info for 56,s. In the tech manual it mentions 3725899 for standard but i think that is for 57.

Thanks
Sheldon

[Gary C.]

Re: 1956 Rear End Casting Code

Sheldon,

Not sure what Tech Manual you're referring to. There's a chart in the 1956-57 Judging Manual.

1956 casting is 3707306.

Gary
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[Sheldon S.]

Re: 1956 Rear End Casting Code

I have the 5th edition and all it refers to that I can find is the 57 casting numbers. thanks for confirming the cast. I just removed the diff and checked the ring gear. The stamp on the outside is AE206, which should be 3.36 ratio, feb 6th which goes with the ser. number of 282 which should be Feb 28th build date. The car is definitely a manual transmission car. After counting the teeth to confirm the ratio it is 3.55. I cleaned up the end of the pinion on the inside and it has stamped in the end GM 22 56 3725841 11 39 It has blue paint on the end of it and on the outside has the blue paint on the housing. The manual says that AE should be with power glide tranny. I am sure this is the original diff. Any ideas and comments??

[Terry D.]

Re: 1956 Rear End Casting Code

Yes someone decided to change rear ends gears. I'm not sure what ideas or comments you are looking for. Unless you bought the car new or knew all the owners lots of things could have changed. Really don't have enough info for any real conclusions.

[Sheldon S.]

Re: 1956 Rear End Casting Code

The Tech Manual does not list the 3.5 gear ratio as available for the standard transmission but there is a letter from Central Office issued on April 9th, 1956 with option changes and lists under standard equipment rear axle ratio of 3.55 to 1 as standard with both the 3 speed and the power glide tranny. Optional equipment lists the 3.27 to 1
In my case they would have had to change the whole pumpkin not just gears and I think getting a new pumpkin with correct dates would have been a bit of a coincidence back in the day as no one cared about anything like that then. The letter is on page 159 of the 5th edition.