68 gmc leaf springs to coils.

[winky]

Converting my 68 gmc frame to coils from a 71 lwb chevy. I've searched and searched but it seams everyone was asking for pics or didn't provide detailed info on doing the swap. Anyways can anyone provide tips? I'll be starting the week and when I'm done I plan on doing an in depth write up for people to go by. Just figured I'd ask if anyone could throw some tips to me.


I know the cross member under the cab is the same. I just have to swap the trailing arm brackets on to it. The rear x member that the Trac bar bolts to appears to be the same as well besides needing the bracket mounted.

My 68 lead Frame does not have the x member the supports the shock that the 71 coil frame has. Seams no holes for it or for mounting the coils.


Thanks for any input!

[lolife99]

Look at this thread:
http://67-72chevytrucks.com/vboard/s...d.php?t=444746

[winky]

Already looked, thanks. It appears that his truck already had the middle cross member, support brackets, and the spring mount plates ( oval plates on bottom of frsme) looks like he change the front x member ( under cab) for one that had trailing arm brackets already. My 68 has the 6 holes to mount the trailing arms to the x member under the cab so I plan on removing the backers and keep the 68 x member. My truck however does not have the x member that is sitting in front of the rear end for the shocks, the spring plates, of support brackets.

[winky]

Notice my 68 frame only has the rear x member that the track bar mounts too. Not the middle x member that the shocks mount too.

Sorry for the bad pics all that I have on my phone.

[lolife99]

I think gringoloco swapped in all the parts from a coil spring truck,... maybe just didn't show it in the thread.
Finding a donor rear frame would be the economical answer.

Companies like CPP sell a shock crossmember and rear shock relocators, and coil spring cups.
I prefer Porterbuilt.
They sell a rear shock crossmember that moves the shocks to more vertical postion, on the front side of the rearend housing.
Check them out at www.pbfab.com
Look at their level 1 and 2 kits.
These are mainly for lowered applications.

EDIT:
Sorry for the confusion on my part.
Gringoloco's truck was originally a coil spring truck that someone had converted to leaf springs.
All he did was convert it back.

[winky]

The 71 frame had the x member right where the frame arch flattens out.

Sorry using my phone not sure how to fix pics at the moment.

[winky]

Originally Posted by lolife99

I think gringoloco swapped in all the parts from a coil spring truck,... maybe just didn't show it in the thread.
Finding a donor rear frame would be the economical answer.

Companies like CPP sell a shock crossmember and rear shock relocators, and coil spring cups.
I prefer Porterbuilt.
They sell a rear shock crossmember that moves the shocks to more vertical postion, on the front side of the rearend housing.
Check them out at www.pbfab.com
Look at their level 1 and 2 kits.
These are mainly for lowered applications.

Thanks, he might have. And yeah I plan on going with pb I'm going to be dropping this one on bags Wichita is the main reason for the coil swap. Hopefully when I'm done I will be able to put together a decent how to on leaf to coils. Seems hard to find good info as far as remove this measure to here etc. I know a lot of the holes will line up but in my case the middle cross member will need holes as well as spring plates etc

[john@thepier]

Put a NO LIMIT back half on it. Easy and very nice set up.

[lolife99]

I edited post #5.
I still think the Porterbuilt Level 1 or Level 2 rear kit is an econominal way to get trailing arms.
And the shock set up is much better than the oem version.

[winky]

I'll be using pb when I put it on bags. Either way I still need the trailing arm mounting brackets swapped I may just mount the trailing arms and springs plates for now (it'll be a shop roller until air bag time) and at that time go with pb crossmember

[winky]

Got the spring plates and crossmember off the donor frame today. Having some problems trying to measure where the plates go... any advice?

[Lees68GMC]

I have 2-1/2 drop spindles and stock springs upfront and leaf springs on my 68 GMC rear, lowered truck no c-notch kit, new ureathane bump stops and aggressive shocks no problems unless you want a much lower ride height

[winky]

I want a much lower ride