1968 GMC coil and 5 lug conversion

[Cooter06]

i can get a complete suspension from a 72 chevy, front spindles and rear coil. i have a 68 GMC with leaf and 6 lug. both are front disc. will this swap be a hellish battle or a simple bolt and go? also is my 2 piece driveshaft going to be an issue? call me paranoid but i wanna know how deep the pool is before i dive in head first lol.

Thanks to everyone in advance

[GMC Canuck]

You'll have to change the complete rear end, not just the axles and brakes. The axles on a '72 are slightly longer. Not sure if the mounting pads on the rear end are different from leaf to coil.

[Cooter06]

i am getting complete rear end, suspension, and front spindles. i was worried about the axel length and coil perches and how it will bolt up and if i will need any extra hardware. i just want to make sure its not going to be a total nightmare. getting all the parts for 350 bucks but dont want to buy it all and find out something like i will need a new rear axle or housing or a fortune in brackets. if i dont get the parts i am just going to remove a couple leafs. it has 9 leafs per side so i am guessing i dont need all 9 for it to ride nice and be functional. not looking to lay it in the grass just want a little softer ride and it to sit level with the front. thanks for the info, the axel part is very helpful. i will be taking measurements this weekend on everything and comparing it to my truck.

[GMC Canuck]

The overall width difference in negligible, but it's enough that drums won't cover the brake shoes if you put '72 axles in a '68 housing.
Hopefully someone else will chime in on the mounting perches.
Here's what mine look like. You can see the mount is on an angle. Coil spring in a '68 with a newer axle. Ignore the shock and sway bar mount, it's all aftermarket.

[GASoline71]

There are aftermarket 5 lug conversion axles that will fit the shorter housing of the 67-70 so you don't have to swap out the whole rear end. I have a set of them from Moser Axles in my 1969 rear end housing. I swapped all the 1972 C15 front suspension and disc brakes over to a 1969 C10 frame. My C15 was leaf sprung out back and the new frame is coil sprung. In my build thread (link in signature line) you can see what I had to do to swap all the 5 lug stuff over. It was pretty easy and straight forward. Also I just installed the engine and transmission into the 1969 frame. The 2 piece driveshaft from the leaf sprung truck fits the coil sprung truck perfectly. Both frames are LB frames.

Gary

[68Gold/white]

To start with...what rear end is in your pickup now? 12 bolt or Dana. There's no easy way to swap the rear ends you ends you are talking about as the previous posts have accurately mentioned???
You'd have to cut the angles mounts off of the 72 rear end, and weld straight mounts on the 72 rear end. I don't think you want to do any of this, I would NOT!!!

As Gas 71 mentioned...
IF, IF your 68 rear end is a 12 bolt, Moser had been (not sure about right now...) advertising "C" clip axles for $260.00/pair. You could have a set made for your 68 rear end and buy (or use the ones off your 72 rear end, if they are any good, or machine-able) two 1972 rear drums. All the rest of the brake stuff will work, shoes, hardware, cylinders, backing plates...

A friend had a set of these axles made for his 67 here, 3-4 years ago. for that price

This is the way I plan to convert my 67 and 68.

None of this applies if you have the Dana rear end. You could still Moser or other differential folks and ask about $$$ of 5 lug axles.

[GASoline71]

I paid about $260ish shipped to my door for the pair of Moser conversion axles through Summit Racing.

https://www.summitracing.com/parts/msr-a3065gmt5

Gary

[Voodoo_Child]

Originally Posted by Cooter06

i can get a complete suspension from a 72 chevy, front spindles and rear coil. i have a 68 GMC with leaf and 6 lug. both are front disc. will this swap be a hellish battle or a simple bolt and go? also is my 2 piece driveshaft going to be an issue? call me paranoid but i wanna know how deep the pool is before i dive in head first lol.

Thanks to everyone in advance

Converting from leafs to coils???
Yes it can be done, use the 72 rear, trailing arms etc.

Does your GMC have the factory crossmember that the trailing arms would bolt to? if not, buy an aftermarket one or grind all the rivets out of the 72 frame.
Get the brackets for the arms.
You will have to source the factory panhard mount from the 72 chassis. Or go with an aftermarket bar that mounts from the right rear trailing arm to the left frame(eec, ccp, no limit etc).

After all the time spent swapping old parts between the frames, I would keep the 72 rearend and purchase a rear trailing arm kit. sale the extra disc brake setup, factory trailing arms, and the 72 frame.

That is what I am doing on my 68 GMC on leafs.

[NGN]

Would the brake line be the same front and or backs , I'm not sure myself just throwing that out there.
NGN
Nick

[GASoline71]

Brake lines are different.

Gary

[NGN]

OKAY here's two more ? Once again I'm not sure my self just trying to help ,what about the cross member where the trailing arms mount can you use the same one now on your truck, are the holes there for the trailing arms mounts and or if not can you drill hole's in the original or do have to replace it for the coil set up. Also for the rear top shock mount brackets will you need them changed. OK just thinking again (ouch) can your exhausts system if it's on and together now still be used with the coil set up. Here I go again, if you do go coil and want to level your truck you'll need the lowering springs. I got ones to lower mine and make it leveled also , just don't remember from who I got the parts from I can find out later. What I got to do the job are four inch lower springs , relocating shock mounts , four inch lower shocks and a adjustable track bar . All from the same place that I can't figure at the moment.


NGN
Nick
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[mvesr]

I have a 1968 C-10 with 6 lug axles. I would like to put 5 lug axles in the 12 bolt rear end that is in the truck now. Can I go to advance, Autozone etc and get axles for my truck and what year will fit the 12 bolt rear that is in the truck now.

Thanks-Mika