New 6 lug rear end in my 56 GMC

[cadman89]

Well after 52 years the rear end in Frances is going further south and it’s time to change it out.
I don’t have a cutting torch or welder or that much money for that matter so I am going to try and keep it simple.
My old girl is a work truck not a show truck so I need to get her back on the road as soon as possible.
I spent Saturday searching salvage yards in the Jacksonville FL area.
The only one I found that I think will work is this 12 bolt out of a 1983 4 wheel drive GMC.



One drum and all of the brake parts are missing off one side but I would replace those anyway.
I sand blasted and primed it to make it easier to work on.



My original springs are 2 inches wide and 39 ½ inches apart.
So that is 41 ½ inches from center to center.
The spring pads on the new rear end are 40 inches apart and the pads are 2 ½ inches wide.
That’s 42 ½ I am thinking I might be able to modify the pads with a plate welded on top.. Thinking…?
I turned the U joint with one axel locked and it went just over 1 and a half times so the gear ratio must be around 3:07 3:08
That will be better than the original because I travel down Rt 95 everyday to work.


http://www.neflnewhomes.com/56gmc/mvc-020f.jpg
http://www.neflnewhomes.com/56gmc/mvc-021f.jpg
http://www.neflnewhomes.com/56gmc/mvc-022f.jpg
Anyone know how to read these codes on the shaft?
looks like KAJ W064 1 E

Any thoughts or comments?
Cadman

[Knothead]

I would elongate the existing holes(1/2 in. each side) in the pads so it would be on center. Then look at the conversion kits sold by Brothers , CPP . All you really need are U-Bolts and Top Plates. But then shock mounts would become another issue.

[BlueJeep]

I would cut the perches off and weld new ones on. They're cheap and it sounds like you anticipate doing welding anyhow. If you don't, your U-bolt plates likely won't fit because that one U-bolt will be spaced away from the spring ....

[cadman89]

Originally Posted by Knothead

I would elongate the existing holes(1/2 in. each side) in the pads so it would be on center. Then look at the conversion kits sold by Brothers , CPP . All you really need are U-Bolts and Top Plates. But then shock mounts would become another issue.

I took yesterday off and pulled the rear end out.
Looks like you are correct the inside bolts will be fine and if I drill 2 holes in the old pads and a new centering hole 1/2 " inward on both sides it will bolt right up fine.
I will keep posting pictures of my "Bolt in a late model rear end."















Cadman