Hi from Minnesota....& a 1st time owner of a square body

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animal

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1973c10

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oldretiredafguy

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Welcome from N. Texas!
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Great looking truck. Always loved the duallys, can't justify owning two of them to the ranch foreman.
 

Babs

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OldBlueDually

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455 Olds
Thanks guys! Hey, can someone let me know how to post in the wanted section? Or do you have to be a member for so long, or have so many posts before you can begin posting in there?

Grit dog, here are a couple pictures of the dual setup on it. The one just shows the rim with hubcap removed. The other picture I took to see what size drums I had so I threw in the dually spacer, and one of the hex nuts/studs for show & tell. As for hauling heavy loads, I do not plan on it. Biggest thing that this "might" pull is our 29' camper. That would be to local campgrounds/parks within a 45 minute drive however, no long distance hauling.

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Big Chip

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It looks to me like you have 3/4 ton running gear. Can you take a picture of the rear diff cover?

This is what the drum looks like on a Dana 70 DRW differential:
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OldBlueDually

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Interesting! Here are a couple other pictures for you. 14 bolt rearend.

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Big Chip

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That drum you took the picture of wasn't on the front was it?


Nevermind, I see what I am looking at now.
 

Big Chip

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This is a Dana 70HD that the dually trucks came with:
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OldBlueDually

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So what do I have going on here? To me, it looks like nothing was ever changed out on it. I hope I can find an RPO sheet, but so far have not. You're correct, that is the rear drum. It is unique as far as I can tell, and I do plan to run it like this. Thanks for the info!!
 

Big Chip

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I think it either started out as a single rear wheel 3/4 ton and had the dually fenders added but there’s a possibility there was a cab change in there somewhere if it shows it’s a C35 (GMC 1 ton). Either way it probably isn’t important if you’re not looking for 100% originality. I’d say most of here aren’t strict “stock” guys so you’re in good company.
 

OldBlueDually

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455 Olds
Now I would like to know the history of this thing! It codes out as a 76 GMC 1 ton. TCS346B517xxx (T-GMC, C- 2wd, S- 454, 3-1 ton, 4-Pickup, 6-1976, B-Baltimore) the numbers after are what? How many were built?

Beyond that until I find an RPO sheet if one exists (doubt it), I really don't know.

Glad you guys are not strickler's for originality :Big Laugh: I do like custom stuff, and things that don't make sense (heck, sometimes I don't make sense anyhow, so it's a good fit!). I do want the body/chrome/interior to all be original however. Lowered, and having a big block Olds under the hood is about all the custom I will get with it.
 

Grit dog

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Very interesting and 99% certain not original, but rather some old conversion kit to turn a srw into a dually with a 3/4 ton axle and srw rims.
Perfect for what your doing. Very unique but not very heavy duty
 

78C10BigTen

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350
Hi Guys,

I am new here on this site, and I am hoping to gain a LOT of knowledge and hopefully find some parts I am looking for (grill, instrument cluster, tail gate)!

I am new to the square body scene, not a stranger to them however. Growing up my dad had a 77 Chevy Suburban/350 (old blue was her name), and a beautiful 78 Chevy Suburban Camper Special/454. I drove them both a lot, and now I miss them!

My new ride for the family is a 1976 GMC crew cab, 1 ton dually, long box. Wanted one for a few years, and I picked up this one out of the blue and it turns out it is a GMC. Has a Chevy grill, and chevy horn button in it, but a Sierra Grande logo on the dash, and the vin states its a GMC.

What I found interesting on this one, are the rims. It has regular style GMC hubcaps front & rear on it, not like a typical dually has.

I look forward to hopefully getting to know some of you on here!



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Welcome and thats a beauty!!
 

OldBlueDually

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1976 GMC
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C30
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455 Olds
Grit dog, so if this is what I have are these common? I dont recall seeing any. What's interesting too is the box sides where the fiberglass fenders bolt on look factory with the hemmed edge, or bent edge where the fiberglass bolts up.

At this point with an Olds powerplant and sitting low I am not super concerned about originality at this point.

Thanks 78C10, just finished doing some patch work on passenger side floorboard and doing a spot now on drivers side. Hope by August to have it road ready!
 

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