Changing the rear spring type?
 

Hi everyone,
My first post on this great site!
With the trailing arm suspension, I was wondering if anyone has ever swapped the double pig-tailed springs in the rear for something else such as pig tail/tangential type? It would seem it would open up more spring choices and the height and rate could be tuned by trimming the coils...
I've searched but haven't found any mention of it, good or bad...
Thanks!

Re: Changing the rear spring type?
 

Bags can be swapped into place. Coil-overs too. Even springs that aren't pig-tailed @ each end if the correct mounts are fabbed.

That being said, I'd guess there's enough spring rate choices available w/strictly bolt in spec'd springs to cover the majority of enthusiasts. Beyond that, it's up to you.

Re: Changing the rear spring type?
 

I think you'll find that a pig-tail spring provides a lot of travel without coil-bind compared to an equally rated spring of another type. I put "beehive" valve springs on my engine to allow me to run some 1.6 ratio rocker arms, the original "traditional" style springs would have coil-bound. It's the same concept.

In my truck, with a 6" drop spring in the rear, there's really not a whole lot of space left to fit a spring between the arm and the frame. So if you're talking about simply swapping another spring into the stock location, I would bet you're going to have a hard time finding something that will fit, in the correct rate, without coil-binding over every bump or any time you put something in the bed.

Re: Changing the rear spring type?
 

Thanks guys. What I'm working on is not actually a C-10 pickup; it's an Grumman Olsonette step van (looks like an old ice cream truck).

The chassis/drivetrain from the factory is a shorter version of the C-10 pickup with the trailing arm suspension (wheelbase is only 102").

I've done a swap on the front to an '87 Suburban 5-lug disc (complete crossmember) and the I've swapped the rear axle in too.

I'll be using it as a mini food truck so it'll be carrying a load, but nothing particularly heavy, maybe 800 lbs. Maybe pulling a small trailer too sometimes. It may vary a bit in load though, and the ability to adjust it easily would be really handy.

I'd like to get a bit more than a six inch drop in the back, though I am not sure how practical it would be - I can't raise the bed like you can on a truck. I know I will need to do some frame notching, and there is about an inch 1 1/2" between the top of the frame rail and the floor bottom for some extra reinforcing.
One idea is of some sort of conventional spring with a helper bag in it. I don't think the internal helper bags work with double pig tailed springs though (?).

I do like the idea of coil overs though. I also came across this coil over shock system:

https://chassisengineering.com/shopD...Id=1056#BuyNow

I could make something like this at the end of the trailing arm and add a bag where the original spring was.

I think I may be talking myself into bags here, LOL Bags are cheap enough that I could buy a set as a starting point...
Thanks again for the input!