trailing arm into 73 or later c10

[txbill]

has anyone swapped a trailing arm coil spring rear suspension into a 73 or later leaf spring c10 ? any problems ? did the cross member fit correctly or did you have to adapt it ?

[trixter99]

Looking into this myself CPP makes a bolt in kit.

[Mattchu60]

I do not think you could just put a 67-72 crossmember into the frame if that is what your asking. The frame is bent downward in the area where the trailing arms attach on the 73-87 trucks.

I have just completed this on my 87' using the CPP kit - Its pretty much the only game in town for this swap. Its a poorly designed kit, but if your good with a welder you can make it work. In the end I'll think it will be worth doing.

[nlped]

I’m curious about this too. I’d love to throw my PB chassis that was meant for my ‘68 c10 Walter under my ‘87. Surely there’s a WAY.

[txbill]

Originally Posted by Mattchu60

I do not think you could just put a 67-72 crossmember into the frame if that is what your asking. The frame is bent downward in the area where the trailing arms attach on the 73-87 trucks.

I have just completed this on my 87' using the CPP kit - Its pretty much the only game in town for this swap. Its a poorly designed kit, but if your good with a welder you can make it work. In the end I'll think it will be worth doing.

thanks for the reply
can you explain what the design flaws were and what you did to fix them?
was there a improvement in ride quality and handling?
Bill

[Mattchu60]

I cant tell you about the ride yet - as my truck is still coming together, it'll probably be a few more months until I have it driveable.

The issues I found are as follows:

- The crossmember they supply for the front - its made of 1/4 steel which is good - but it does not match the frame profile well. I had to heat/bend the driver side down to mate up to the frame.

- the real issue is the spring bracket/c notch. The spring angles are way wrong. Its hard to explain here - but the springs mounts on the brackets are tilted so the spring is pointed backwards about 15-25 degrees, while the trailing arms themselves are also tilted toward the back. The end result is that spring forming an arc when installed as the mounting surfaces are not even close to parallel. My solution was to cut the brackets apart, and reweld them where I think they make more sense.

I called and talked to CPP about these issue - the response was "we hear that sometimes" and no further help or solutions were offered.


- The shock bracket fits fine. The shocks are way inboard in their design, not sure it will really help the ride much - I made my own brackets in the end but I used their shock crossmember to give the frame some strength.


I would share pictures, but I have photobucket and sharing doesnt seem to work from them any longer.

Its a good kit for a starting point - I will say that.

[nlped]

I’m really curious about this. I’m going to pull a tape measure tomorrow evening to compare the frame widths behind the front crossmember to see where they begin to differ.

[bluex]

I converted mine with a porterbuilt kit. I dont think they offer it anymore. It had it's faults too but the ride an handling now is awesome. Theres a link to the install in my signature.

As far as factory parts you could possibly make it work but the crossmemeber needs to hang down out of the frame some. The spring mounting point is also wider than the factory 73-87 frame.

All in all it depends on what goals you have for the truck. If I had it to do again I would probably do a 4 link but thats mainly because I want the truck lower now lol.

[bluex]

Originally Posted by nlped

I’m curious about this too. I’d love to throw my PB chassis that was meant for my ‘68 c10 Walter under my ‘87. Surely there’s a WAY.

Make New cab mounts an you should be fine. I have a 71/72 axle under my truck so as long as you adapt the cab, core support and bed mounting to that frame it should work.

Honestly I think that might be easier than trying to make the trailing arms fit a 73-87 frame.

[SCOTI]

Originally Posted by nlped

I’m really curious about this. I’m going to pull a tape measure tomorrow evening to compare the frame widths behind the front crossmember to see where they begin to differ.

Frame widths where the x-member would bolt-in are the same. But, the 73-87 frame kicks up in a different location vs. a 63-72 & this is where the different x-member is required for d-shaft clearance.

[moregrip]

I believe "HotRods to Hell" sells a trailing arm kit as well

[Loco83]

Do they still sell this kit?
http://67-72chevytrucks.com/vboard/s...d.php?t=549029

[SCOTI]

Originally Posted by Loco83

Do they still sell this kit?
http://67-72chevytrucks.com/vboard/s...d.php?t=549029

I don't know if they/PB still offer it but 'Bluex' used that kit & encountered several issues w/his install. It wasn't exactly bolt-on easy from what I read which is unfortunate. I would do a 4-bar kit vs. Truck Arm swap based on what I've read about the issues w/the bolt-in swaps offered.

Of course, if a guy can fabricate, it can be done by just purchasing some select pieces & building the remainder to the specific chassis.