I have a dana 70 hd out of my 89 crew cab dually and I want to convert it to SRW. i have found I need the shafts and outters including brake plates and so on to do this, I just dont now what they came in to look for. Thanks

You cannot just 'convert it', that axle is almost 8' wide with the tires bolted on. You can bolt on a single tire, unless you want to get into cutting tubes

Havent seen a gmc or chevy with a srw dana 70 rear yet. Ive seen lots of dodge's and fords that way and its the cheapest route to go for a donar axle.

Some 88 and newer 1ton IFS trucks had D70s. I have one out of a 89 IFS 1ton Chevy, SRW.

Some 88 and newer 1ton IFS trucks had D70s. I have one out of a 89 IFS 1ton Chevy, SRW.

Ah yes... the 3U variant that's a biotch to regear because of the odd-ball offset. ;) Otherwise you still need to move perches to make it work.

If you like scavenger hunts, try a D70 from a 70s/80s Ford cab & chassis. They should also have 40.5" spring spacing.

Ah yes... the 3U variant that's a biotch to regear because of the odd-ball offset. ;) Otherwise you still need to move perches to make it work.

If you like scavenger hunts, try a D70 from a 70s/80s Ford cab & chassis. They should also have 40.5" spring spacing.
Damn u beat me to it. Chances are pretty good it's a 70U since it's an '89. It's still 35 spline but iirc some of the bearings are smaller than a standard 70 or 70HD.

What brand truck is it out of? Is 70HD cast into the case?

Do you have a pic of it? I have been trying to find ways to differentiate (sp?) between the different 70's. I was sure the one I found at the yard was an hd, the tubes were fawkin huge, but they do taper down right before the brake mount flange. I ran the bom and it turns out of its out of a '73 Dodge srw 3500 and its just a std 70. Of course I still used it (I did gear it to 5.86, just so I could laugh at 14 bolt owners wishing they had more gears :evil: ), and she is still treatin me well. :smokin: I really don't ever see myself using a smaller rear than a 70 ever again. :grinpimp:

My 1988 GMC 1 ton 4X4 with IFS has a 70HD in it.

Got more info? tube size? ratio? BOM?

Would be cool to verify they exist.:cool2:

Got more info? tube size? ratio? BOM?

Would be cool to verify they exist.:cool2:


It's ouside in the dark will get it for you tomorrow.

OK here's what I've got. It's a 1988 GMC 1 ton 4x4 70-3HD 3.73 gears 3 1/2 inch tubes that don't neck down at all. BOM is 1R76KW1J17C246 2NA. Now the J and the last 6 are questionable but that is what I have.

My 1988 GMC 1 ton 4X4 with IFS has a 70HD in it.

i have the same truck w/ the same rear end w/ 4.10's

Thanks for posting that, I had always been under the impression that those years of chevs only came with the 70U. Good to know.

Is the HD cast into the pumpkin or? Can you get a pic of the tube end?

Actually, maybe I'll start a new thread so I don't jack this anymore off topic.

My dually rear end had 70HD cast right into the rear end it is out od a 89 crew cab dually. I just have no need for a dually. i guess i will get rid of it and look for a donor. GOnna run the 14 FF for now.

Hey I just started a thread for the purpose of collecting all the 70 knowledge here into one place, linky... (http://www.pirate4x4.com/forum/showthread.php?t=522333)

I think a 3HD is diffferent animal from a HD. Maybe what we've called a 3U until now is actually a 3HD.:laughing:

The 3HD has a 3.42/3.73 ratio split.:confused: ARB indicates 'special fitment required' also.