suggested to do a writeup for here like this also
 

I know theres about a million threads about this, hell I have just read about 30 or so, but cant seem to figure it out, I am powdering my rear, swapping from 6 lugs to 5 and installing a stock 71 c10 posi unit into this rear.

Originally its out of my 1970 c10 coil 2wd 6 cylinder truck, running 3.73 gears, I want to replace all the bearings as well as seals.

Can someone help

tks

Re: Help me identify my rear
 

I don't understand your question....sounds like you have a 70 rear end and you want to install 5 lug axles??...Is that correct? I'm sure others know, but to my understanding the 70 axle housings could be either a narrow or wider housing pending on its production date....the 67-70(early) were approximately 3/4" per side or 1.5" narrower than the 70(late)-72 rear ends....if by chance you have the later rear, you maybe able to swap in axles from a 71/72 truck or buy the ECE conversion axles or check with Moser(?)

So...please measure from backing plate to backing plate....this will help determine

Re: Help me identify my rear
 

Wow! How I messed that up, I need to know if it is a Dana rear or a HO35. When buying bearings for the rear axles and diff carrier I get lots of options regarding Dana rear ends and HO33,35. I am not sure what one I have?

Thanks

Re: Help me identify my rear
 

GM 12 bolt truck...:chevy:

Re: Help me identify my rear
 

longhorn got it but this might help explain the difference for you.

http://coloradok5.com/axleguide.shtml

Re: Help me identify my rear
 

Thanks guys, so its def not a Dana rear, tks

Re: Help me identify my rear
 

nope...looks like a....

GM CORPORATE 12-BOLT
The stronger 12-bolt, with an 8 7/8-inch-diameter ring gear, can be found in various 1964-82 GM 1/2- and 3/4-ton rearends.