1961 rearends ---need some advice

[1963c-10]

I have the date codes and rearend gear size info, but can someone help me with what rearends came in the 61 c-10's? I know some had dana's and some had what im guessing were GM corp 10 bolt's (round housing). Which were the better rearends. Also...how does the 10 bolt round rearend compare to the GM corp 12 bolt used in 63?

[jchav62]

I'm not sure of the exact names of the diffs, but '61 Apache 10's came with what you refer to as the "Round 10 bolt" (that's all I've seen anyways). 3.90 is the more common gear ratio, but some came with 3.38's.

I'm sure the gurus will chime in... JC62

[1963c-10]

I just got a 61 donar truck w/21,000 miles. Had planned on pulling the rear (hope its a posi) and if so installing in my 63. Are the 10 bolts a decent rear end? I just dont have any knowledge on them. Im more familiar with the 12 bolt 8.875 rears used from 63 on

question # 2.....need some input on two piece driveshaft vs 1 piece. My 63 has a one piece driveshaft and Id rather retain that.

[62 Longbed]

If I remember right , you'll have to do some cutting / welding of the brackets since a 1960-62 Rear End will not directly bolt into a 63-66 frame ... X-Frame vs. conventional frame ..

[BLK65K10]

62 Longbed is correct. The 60-62 rear trailing arms come back at a different angle and are wider appart. As far as the Dana 44 it was mostly a GMC rear axle and was leaf sprung so it isnt a direct fit either. The only bolt in rear ends are the 63-72 chevy 12 bolt. The 12 bolt is a more durable axle and easier to get parts for than the "round 10 bolt". I would stick with what you have and rebuild it if needed.

[LostMy65]

As others have mentioned, I don't think the 63-72 12-bolt is a direct bolt up to the 60-62 trailing arms - The perches are further apart on the 60-62's

[Captainfab]

Yep, I would stick with the 12 bolt. Better selection of parts, and aftermarket support. If that rear end is a posi, I would sell it to someone with a '55-'62 truck, and put that money into your 12 bolt.

[Calvin66c10]

hey, out of curiosity whats the oem gear ratio for a 1966 c10 12 bolt? I always thought it was 3.73 but i have yet to actually check.

[1963c-10]

Ok, well then the 10 bolt will stay under the frame and it'll be my new trailor that im building. Now just gota find a short stepside bed.

[BLK65K10]

Originally Posted by Calvin66c10

hey, out of curiosity whats the oem gear ratio for a 1966 c10 12 bolt? I always thought it was 3.73 but i have yet to actually check.

3.73 was standard equipment in 1966 12 bolts but 4.11 or 3.08 were available as options.

[markeb01]

For what it's worth, my 1960 GMC 1/2 ton has trailing arms and a Dana 44 from the factory. If you can find one it should be a direct bolt in. And Dana axles remain very popular with the 4x4 crowd so different gear sets are easy to find. If you have a bunch of vintage GMC's in the local wrecking yards, it might be an easy solution.

[1963c-10]

I find 90% chevy in our local yards. But I'll keep my eyes peeled.

[Calvin66c10]

Originally Posted by BLK65K10

3.73 was standard equipment in 1966 12 bolts but 4.11 or 3.08 were available as options.

Thanks, Ill have to look into it then. I believe it has 3:73s. Ill look on the build sheet behind the seat to see if they special ordered different gears