Well, not quite towing with an '86 Corvette, but here goes:
I have mounted a complete '86 Corvette rear with stock spring under my '57 Suburban, using a Flat Out Engineering kit. Works great, comfortable even with the stock Corvette spring, as long as the truck is empty!!!
According to my info, the weight on the rear of my Suburban is about 300lbs heavier than on the rear of an '86 Corvette, not that much, really.
Anyway, I sometimes tow a 4000lbs camping trailer with my truck and I have to tighten my weight distribution hitch like crazy to do it. I have recently towed 5000 miles in a month like that, so it works, but I would like to "help" my rear suspension a bit!
I was not too lucky with air shocks (leaks) and I fear the bigger effort on upper shock mounts; coil-over do not give much easy adjustability; I could not find an airbag kit for a Corvette rear; I fear that a stronger transverse (steel) spring would make the ride too stiff, too "truck-like".
So, what are you guys' suggestions? Any thoughts?
In particular, can I use airbags between the stock spring and the diff mounting-wings, or is this too much for the plastic spring?
And do not tell me to stop towing with a Corvette rear, I love my truck that way, I just need to fine-tune it!
Thanks!

 

I can understand that you want you "cake" and "eat" it too. You are placing an awful lot of faith in a fiberglass spring that was designed for a purpose other than what you are using it for. You may have to have two set-ups. One for hauling...one for cruising.

Contact Chip Foose and ask him....he went to a design school.

...OR...

Why don't you contact a professor at a University or school that deals in automotive design. Maybe he/she can make this "issue" you have be a project for his/her students....and they can learn and get graded on it...or realize it is something that is not done for reasons that may not be so obvious. You never know. Heck it may work. This way you will actually know what it would take to make a rear end for a sports car be used for a truck that hauls a heavy payload.

And for what it is worth...I seriously doubt anyone is going to respond to this post due to what you want an answer to...heck...I may be wrong...but....mainly because it is quite contradictory....much like hiking boots on a ballerina.

DUB

 

57 burb and towing . I would have gone Ford 9 inch and truck arms , maybe air bag it , or just plain coils .
Had a 68 burb , never should have sold it .Did lots of towing with it .
Your asking allot from that glass spring .

 

While the C4 was never designed for towing and it was not recommended, there were trailer hitches made for the C4. The weight placard that was placed on the driver's door showed a maximum cargo capacity of about 450 lbs. Now considering that the weight of two passengers and maybe some luggage for a trip would bring that value to its maximum. So with the additional weight of the truck, that leaves maybe 150 lbs. that the spring can handle.

Moving the batwing and the spring to a different vehicle such as your truck doesn't really change the C4 cargo weight maximum. It's not the truck, it's the suspension!

You also have to consider the spring itself. Is it a base spring or a Z51 spring? The rates are different. What about the C4 sway bars? Did you install them? They are part of the suspension design.

You mentioned that you tow 4000 lbs. Even with a WD hitch, there is still a good amount of tongue weight. That weight is part of the total weight on the C4 spring. I'll bet that you are waay over the limit for that rear suspension setup.

You say "don't tell me to stop towing.." Well, I think you are way beyond the design limits for what you have and if something breaks, you will be in real trouble. And remember there are other cars on the road. So I do suggest that you find a suitable tow vehicle and one that is set up properly for towing.

 

This 1980s vette was towing with no problems. Coil over shocks may be the best answer to your suburban, with c4 suspension issues

 

I realize that I may have to change the spring for a steel one... Mainly because I am tired of leaky air springs!
My main question is how to have a truck that is comfortablke empty and also able to carry the tongue weight. I do not believe coil-overs would give me that flexibility: with coil-overs, you choose the spring rate and you are stuck with it, I do not want to have to crawl under the truck to adjust the springs each time I tow! An automatic load leveller system would be the best!
Air shocks were (and still are) available for C3 Corvettes, but they are too short for my set-up (I have tried)...
I have not been able to find an airbag kit for a Corvette, but I wonder if, with a slightly stiffer steel spring, I could use an airbag between the spring and the differential-mounting wing?...
And once I sort out the suspension, this truck will be a great tow vehicle, totally suitable for the job! And looking good doing it too! No need for a 9" either. All I need is to put a bit of thinking into it, and figure out what will work...
By the way, what is the rating of the stock, base spring for an '86 Corvette? That will give me a place to start to have a custom spring made.

 

Can you add some coil over shocks to go with the leaf spring and use both ?

 

I'm not so sure the batwing can take this weight. Coilovers would at least shift most of the weight off of the batwing but then puts it on the lower shock mount which is not designed for that kind of weight either. There has got to be a better way to give you a soft ride empty then a corvette rear end.

 

Yes, I was also thinking about that too, using these "load-leveling" shocks, the ones with the variable-rate helper spring on the outside: empty, the Corvette spring carries the truck, loaded, the helper spring takes over...
That could work, as the kit I have used for mounting the Corvette rear came with new, strong upper and lower shock mounts...

 

Why stiffer steel spring, there are stiffer composite springs available. GM developed the composite spring for the C3 IOT to remove weight and one benefit was that spring life was increased (no metal fatigue)
I was recommending coil overs since you could choose the perfect spring rate and set the ride height.

Mike

 

Steel springs are easier to find and have custom-made, many manufacturers of steel springs for the camping trailer or trucking industries (for instance) would be able to make one locally (if they are interested, of course!), whereas composite springs are made by more specialized shops, harder to find, more expensive...

 

The load is going in one direction that the wings are built for.

There are other aftermarket springs available.
The least expensive alternative is going to be an "airshock" package.

 

I have not had much luck with airshocks:
first I used C3 Corvette air shocks, which were too short for my set-up, then I used Ford Aerostar shocks (picked according to length and vehicle weight), but they really did not help much, they would barely raise the empty truck by an inch, so... And even installed by a pro (after I gave up!), I still had leaks issues, I had to refill them every other day... Not good!

 

Vette Brakes and Products can make you a rear spring in fiberglass to whatever you need.

I talked with Gary about a week ago and he mentioned they have made then to 1000lb.

I seriously doubt that the photo that was posted of a Corvette towing some stuff was any where near what you are towing. You are pulling a trailer that is more than the entire curb weight of a 1986 Corvette. You are putting a lot of trust in the ring and pinions ans shafts.

I would seriously look into talking with design engineers on this....but...you are going to do what you want. The only thing I hope is that when something goes really BAD...and it will...just give it time...no one is around so you don't hurt innocent people. You can be opening yourself up for some serious liability. Just because you can customize something...does not actually make it SAFE.

DUB