Some Diff info?

[handsomerob]

hello all,

I'm new hear, and I'm looking for some info on a Dana 60 from a 72 C20 pickup. Basic questions such as what where available gear ratios and out of thos what where the most common, then what size axles where used and spline counts. We are doing a project on the above truck and need to beef up the rear end, we will be installing a locker probably Detroit.

As a bribe for info I will promise some pics of the truck and powerplant after some responces

Thanks in advance.

[handsomerob]

No takers? no one has info on the dana 60's in these trucks?

[292farmer]

what motor and tranny is in the truck? big blocks usually had 3.54 gears inline 6's usually has 4.11 4.56 my c25 gmc has the 4.56 gears in my dana 60 behind a 292i6/sm465 combo but im sure you could order a different gear for your truck back then like a 4.56 behind a bb hope this helps

[handsomerob]

Well originally it had the 8/400 or 396 Big block, oh it's also a Cheyenne if that makes any difference.

Thanks for the info so far.

[292farmer]

so far as i know should be 3.54 gearing, if u can look on the axle tube and on the diff housing some have a tag with the gear ratio some are supposedly stamped on housing but ive never found one on mine.

[handsomerob]

only numbers stamped on the diff are:

C30255

and

243-71

[292farmer]

243-71 might be ring and pinion teeth count comes out to 3.42 which was an option for the dana 60 im sure. hopefully some will add their two cents and verify that or correct me lol.

[handsomerob]

Well as promised I will post a few pics of the project we are working on . . .









there she is, 1972 with AC, Auto, yanked the 427 out of it and are prepping it for a 572 with a 4L85E.

[handsomerob]

So 3.42 is most likely what I am dealing with then? anyone know what the axle spline counts where on these? or the axle shaft diameters?

Curious to find out as much info as I can before I open the diff up.

[292farmer]

im jealous ive been wanting a 572 for my truck, grrrr lol i believe while researching mine its a 35 spline count, but i may be wrong so verify that some other way if u can, sorry cant be of more help, im assuming thats the 620hp version and not the 720hp? i know chevy hiperformance dropped the 450hp/502ci gmpp cam in that motor and it made a little less hp like 590 but torque increased +60lbs ft at each rpm from idle to 4500rpm made it great for a truck. food for thought. did u keep the stock cam or inject your own?

[Longhorn Man]

you will have a broken dana soon if that 572 i going in.
3.54 gears in a dana were the standard set up in a big block/auto C/20 truck.

[airdale94]

That double pumper looks like a toy on there!

[Blazer1970]

The D60 full floaters like you have are mostly 4.10 or 4.56 gears. 4.10 is more likely. They have 30 spline shafts (about 1 1/4"). These shafts are about the same strength as what was used in 12 bolts, and later 10 bolts. Not a good choice for the torque you are planning as Longhorn man has already pointed out.

[handsomerob]

To answer a few questions, Yes this is the 620 HP version, we wanted it streetable. This is not goin to be a drag truck or anything, more sleeper street truck, smoke show, make a lotta noise truck. we have a ladder bar system we are putting in it and we plan on beefing up the rearend, hence all the questions. Ie: Detroit locker, stronger axles etc.

Other then that the truck is going to remain stock. it is going to get a rocker repair and the paint is getting some touchup and polishing, but thats about it.

The Dana 60 must be fairly strong because this truck was running around with a 427 in it and it made quite a lot of power. obviously not as much as the new engine but it's no push over either.

[Longhorn Man]

Originally Posted by Blazer1970

The D60 full floaters like you have are mostly 4.10 or 4.56 gears. 4.10 is more likely. They have 30 spline shafts (about 1 1/4"). These shafts are about the same strength as what was used in 12 bolts, and later 10 bolts. Not a good choice for the torque you are planning as Longhorn man has already pointed out.

If it was originally a 3/4 ton, with a big block, then the gear was 3.54. The dana could have 4.57 gears, or 4.11... but were very uncommon, and the 4.57 wasn't avalible in 3/4 ton big blocks.
The 4.10 and 4.56 were eaton gears, not dana gears.

[handsomerob]

Originally Posted by Longhorn Man

If it was originally a 3/4 ton, with a big block, then the gear was 3.54. The dana could have 4.57 gears, or 4.11... but were very uncommon, and the 4.57 wasn't avalible in 3/4 ton big blocks.
The 4.10 and 4.56 were eaton gears, not dana gears.

Yes it was originally a big block, the 8/400 C-20 it's all original except there was a 427 dropped into it in the past 10 years.

So I should be expecting 3.54 ratio and 30 spline axles then?

[Big-Blue]

Longhorn Man.....with over 78,000 posts you have probably forgotten more than I will ever know about these trucks, but I am pretty sure my K20 small block rig came with these 4.10's in my Dana 60.

Note the Dana....41.10 text...

Am I missing something?

[eagleuh1]

My 68 C20 with Dana 60, 327, TH400 has 4.56 gears. All original.

[Longhorn Man]

my comment of 4.57 not being avalible in 3/4 ton... I ment one with a big block. Everything I've seen and read indicates the danas had 4.11 and 4.57s, and the eaton/corp having 4.10 and 4.56.

[KFreddy]

Hi,

Sorry for the quasi hijack, I'm just curious about your build and the 4l85e that your planning on installing with that 572. Is that the new 4l85e Supermatic part # http://paceperformance.com/index.asp...&ProdID=238851
If so what TCU are you planning on using to control it? What Tranny cross member or are you fabing your own. I am putting together a build list for that transmission swap hopefully do be done by the end of March. I'd be happy to compare notes.

Thanks,

-Fred

[handsomerob]

Yes that is the correct Tranny I will be using, and I will be using the recommended controller from GM

GM 12497316 Transmission controller

Also going to be using Abott enterprises Cable -X system to continue use of the stock Speedo.