How can I easily calculate the gear ratio in a torque tube rear end? Can't count turn of the driveshaft. Don't want to pull the plugs, tranny in 4th (1:1), push truck, count engine turns and wheel turns.

I believe that my '54 3100 has a '50 rear end. Date code on housing: H E1 21 = 1950 3100 Regular Rear Axle, Detroit plant, Jan 21, 1950.

EDIT: I JUST SAW THE GHOST OF A "2" AT THE END OF THE DATE CODE IN THE PHOTO. WHAT DO YOU THINK IT MEANS? NEVER NOTICED IT BEFORE.

1950 ratio is 4.11:1, 1954 ratio is 3.90:1. The diff is quiet and causes no problems. The speedo seems to mirror the speed shown on my GPS. I don't push it, but I know that it will run over 50mph.

> Rear axle cover
> Rear axle date code
> 1950 GM Resto Pack serial numbers

I have a buddy who is hot rodding his '54 and will have his rear end available. I may buy it. Anything to look out for?

Thanks for your help,

Last edited by LonnieC; 06/30/2012 4:02 PM. Reason: "2" at end of date code
- Lonnie
My '54 3104
Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post.
lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

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