Rear end question

[CarterD2015]

I need to identify the correct rear end from my 72 c10. My father talked me into using a ford rear end because it already has disc brakes and posi. He was the brains of the operation but he recently passed away and I have no idea how to finish the rear end swap. I still need to weld the pads to the axel tubes. I am concerned that if I do this incorrectly that the truck could track funny and or vibrate.

I considered my options and don't want to spend 3-4k on a new bolt in. So I decided on putting the original one back in. That way I can get the truck on the road and worry about upgrading later. The problem is I can't seem to locate it in his parts pile. I have included a pic of the one I think is it but need confirmation.

Thanks

[CarterD2015]

Here is a pic of the numbers from the other side

[GASoline71]

If it's a 71 C10... the original rear end would be a 12 bolt truck rear end. Post a pic of the rear cover.

Gary

[CarterD2015]

Those casting numbers are from a 12 bolt. My problem is that there is another 12 bolt in the pile. It was too dirty to read the passenger side castings. The drivers side was GM 58.

[leftybass209]

You'll have to wire brush the top of the passengers side tube to ensure which of the two axles you may want to use. They could have different gears, so it would also be beneficial to pull the cover and verify the gears. Are they both 12 bolt, 5 lug with trailing arm brackets (or no brackets)?

[CarterD2015]

Yes they are both 12 bolt, 5 lug with trail arm brackets. At least I think they are trail arm brackets. They are pads set at a 30-40 degree angle from the axel tube. I would upload more pics but those two are all I took and they are 75 miles away. I will be up that way next weekend and can take more then.

[CarterD2015]

What should the distance between the trail arm pads be?