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| | | | Joined: Oct 2010 Posts: 1,232 'Bolter | | 'Bolter Joined: Oct 2010 Posts: 1,232 | 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 numbersI 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 3104Photos 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. OLD STUFF ... houses, furniture, cars, wine ... I love it all | | | | | Joined: Aug 2004 Posts: 1,418 ODSS Lawman | | ODSS Lawman Joined: Aug 2004 Posts: 1,418 | If its a 50 1/2 ton, it is a 4:11 gear. Going from 4:11 to 3:90 is not worth the trouble in my opinion. Too small of a change.
If you install Patrick's 3:55 set, that will make your truck cruise at 70 all day long....
To confirm what you have you will need to pull the diff cover and count teeth or check the stamping on the pinion gear itself..
SWEET Sergeant At Arms: Old Dominion Stovebolt Society BUNS?!?!?!Where we're going, we don't need no buns.....1950 GMC 450 1951 Chevy 1/2-TonThe GreenMachineIn the Stovebolt Gallery | | | | | Joined: Sep 2001 Posts: 29,270 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,270 | HE 12 12
HE = 1950 regular 3100 rear end
12 = December
12 = 12th
?
I agree with SWEET, unless you want a correct-date rear end, and your '50 rear end is OK, I'd only take the 54 rear end if I had a place to store it and if it was a freebie.
| | | | | Joined: Oct 2010 Posts: 1,232 'Bolter | | 'Bolter Joined: Oct 2010 Posts: 1,232 | Thanks guys. Guess you're right. Everything works well and it looks like I would pick up less than 3mph with a 3.90 at the same RPM as my 4.11 at 50mph. I'll see if I can get if for near-free. Don't have a clue where I can store it in my overstuffed garage. Maybe someday I'll try to get the truck back to all 1954.
Tim you had shown me the 1950 meaning of the "HE" designation a few months ago. Duh - thanks for showing me the correct date. Glad I found the ghost "2".
- Lonnie My '54 3104Photos 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. OLD STUFF ... houses, furniture, cars, wine ... I love it all | | |
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