The Stovebolt Site Forums The Parking Lot '60-'66 Trucks 1963 GMC Differential I.D.

Hey all,

I've got a 1963 GMC 1/2 ton 4x4 with 3.54 gear ratio in front/rear differential. I just put a T5 5 speed tranny in and I would like to switch my gearing down to a 4.11. I am going to leave a webshots link at bottom of this page with pictures of what I have and I was hoping someone could I.D. which type of spicer's I have (I think they are spicers) THese are 10 hole and the cover is only on one side.

I also would like to know if anyone wants to trade your 4.11" for my 3.54's or perhaps something else I have might interest you. Here's some of what I got lying around.
1. A complete spicer front-end just like in the pictures except the gearing is 3.73.
2. A complete rear end with 3.73's but I think this is from a 60's chevy (17 spline axles)(not a spicer)
3. I have a complete Rockwell T-221 Transfer case
4. Original A.C. Compressor
5. Grille for headlights

Please let me know if you can i.d. what I got on my truck as I have heard that certain spicers are rare to find parts for.

Thanks so much!
Here's the link: http://rides.webshots.com/album/580070853FRkNnN

Shane Hamilton
Warrensburg, MO

I'm nearly certain you have a Dana 44, same as in my 1960 GMC. Your last picture looks identical to mine:

[IMG]http://img534.imageshack.us/img534/3800/exhaust02.jpg[/IMG]

These are very common axles, you should have no problem finding parts. They are very popular with Jeep guys and have been used in Fords and Chevys as well. You probably already know you will need the “other” carrier to go to a 4.10 ratio. The break is 3.90 I believe. 3.90 and lower (higher numerically) gears require one carrier, and 3.70’s and down require the other. Mine originally came with 3.90’s from the factory, which I swapped for 3.08’s years ago when I ran a turbo 350. About 7 years ago I switched back to a manual 4 speed and swapped the rear axle to 4.10’s requiring a change back to the other carrier.

Check with any local 4 wheel drive or axle shop and they should be able to fix you up. On my first swap I went with used gears/carrier out of a Chevy Blazer and they worked fine for many years, so this might be a consideration if money is tight.

The only oddity I found on my axle was the brake backing plates. They do not use a conventional emergency brake cable mounting hole. Instead they had a separate bracket that bolted to the cable and the backing plate. Replacement cables do not accommodate this mounting setup. After searching hundreds of vehicles for conventional backing plates, I gave up and had my son fabricate new brackets so I could install aftermarket cables with conventional retaining clips on my original backing plates. Perhaps these odd cable attachments were eliminated by 1963.

That's a "Dana 44" rear axle.
It is THE most common rear axle ever used; it's found in everything from '50s Studebakers to Checker cabs to Jeeps to Broncos to Jags, Corvettes and even Vipers. (variations of, anyway).

You'll have ZERO problem finding a new/used carrier for it, or gears. I have one in my '61, and got a take-out carrier from a Jeep guy off ebay, and bought new 3.42 gears directly from Dana (because I prefer OE factory gears when available).

The early Dana 44s had a more course spline count (I THINK it was 17-spline) and a lot of Jeeps had them. Mine has 30-spline axles, so when you shop, know that there's a difference in carriers.

If your other "spicer" has the same rear cover as the one shown, or has "44" cast right into the housing, it's a Dana 44 also.

If it's got 12 bolts on the rear cover, (but the same general shape), it's a truck 12-bolt.

-Brad

I too think its a Dana 44 YOu can contact precision gear and find parts that will drop you down as low as 3.23 Idid that with mine.

Jake

Thanks Guy's! I guess the only way to tell what spline carrier I have would be to open it up and see?

Shane
Warrensburg, MO

Yeah, you'll need to pull an axle and count the splines.
You can do that by pulling the axles, without unbolting the dif cover; they're not C-clip axles. Unbolt the bearing retainer/backing plate bolts and slide the axle out. (though you might need to apply some oomph, depending on how seated and reluctant to come out they decide to be)

-Brad

Sweet! Brad, DO you know if that's the same for both front and rear ends? THANKS

Shane

That, I don't know for certain, but I would think it SHOULD be. The dif loads into the housing the same way.

-Brad