I have a '75 Corvette currently in pieces getting restored. Among the many things that need to be fixed/upgraded is the suspension.
I'm looking to get a kit that can replace most of the current suspension systems and came across these 2:
VB&P GRAND TOURING PLUS SUSPENSION KIT
VB&P STREET & SLALOM SUSPENSION KIT

I want a street car, so I don't need to have the stiffest suspension ever.
What is your opinion on these kits? Did anyone try them?

I feel the Street&Slalom might be too harsh with 550lbs front coils, specially given that I might need to trim them a bit to lower the car.
Will I regret going with the softer Grand Touring?
Can you recommend some possibly better kits?

Thanks!

 

That's the kit I installed 15 years ago. No regrets.

 

When my 79 Vette was new I installed Street&Slalom with 550lbs front coils and poly ends on the smart struts 1 1/8th front bar and 3/4 rear sway with spring end links.

the 550 spring is one inch shorter in ride height. I had to space it up with a 3/8th inch spacer because of my low profile front tires.

I then found the rear to be lacking so I installed a 500+ pound rear spring.

I just got so used to driving it that any time I drove a lightly sprung Vette that I didn't even feel safe going around turns in them. I don't like driving them. I like solid with modern performance tires.

 

I have the Grand Touring package on my 76. It's definitely a step above stock

 

I have the 550 front spring cut 3/4 of a coil with 360 pound rear spring and it rides better than stock.

 

Same (well, 370lbs rear actually)! Also bigger front bar and rear bar added. Much better!

 

Don't be put off by a stiff front spring it sits forward of the engine and effects ride less than the rear spring that's about 2 feet from your backside.

 

My 78 came from the factory with the gymkhana suspension. I made one change at a time over the past 30 years to improve the factory sport suspension and my car today, rides, handles, and steers MUCH better than it did from the factory. I have this suspension today:

Putting the factory gymkhana suspension on a 74 is easy (I would recommend the 78-82 F-41 settings):

front springs 550 lbs (base suspension is I believe 350lbs)
rear steel 7 leaf spring of 292 lbs (base suspension is 192lbs-9 leaf)
Front bar-1 1 /8 inch (base is 7/8 inch I believe)
Rear GM style Only sway bar 7/16 inch (no rear bar base suspension)
Bilstein HD's or Sports

A better gymkhana suspension like I have had for many years with superior ride AND better handling:

Front 550lbs coils cut 1/2 coil for lowering
Upper and lower front Poly control arm bushings
custom blueprinted/rebuilt OEM factory steering box
rear Composite 360 lbs spring
Bilstein HD's Front with poly bushings on top
Bilstein Sports rear
factory 1 1/8 inch front bar with all poly bushings
rear 3/4 inch GM style bar with poly bushings
255/45/17 ZR ultra high performance summer only tires
Competition adjustable strut rods with heim joints
Front Spreader bar-Speedirect

My 78 handles almost as good as my 2008 Chrysler 300 3.5L V6 with Bisletins all around, Chrysler front strut brace, Hemi V8 aftermarket front and rear sway bars, and 245/55/18 ZR tires...with a firm not harsh ride..My 300 is stiffer....

FWIW-I would not purchase a kit depending what you have now since both kits have a NON Factory style rear bar (buy a 7/16 GM style rear sway bar and endlinks), and as seen as my suspension above it is best in some cases to mix and match the Bilsteins (fronts HD and rears Sports) for the best ride and handling. For a basic Sport suspension, you would need:

Bilstein HD's Front and Sports in the rear-$400
1 1/8 inch front sway bar-$160
7/16 inch rear GM style only sway bar-$180?
550lb front springs-$90
360 rear composite Spring-$350

Roughly Total-$1,200

 

Seems that a lot of you went for the 550lbs front and even cut the springs a bit. I thought it would be too hard for a street car but seems it's fine. I might end up getting the Street&Slalom then.

 

The front spring is north of the engine and doesn't affect ride as much. The rear spring is closer to where you sit. Composite springs ride much better.

 

It's a nice kit, I had it before I went coil-overs. Replace the Poly Smart struts with the 42211 though.

 

The VB&P Performance Plus package I got for the 63 is awesome. Just saying.

 

I am installing the performance plus package on my 72 BB, exited to se how it works when i can drive it..20 inches of snow here now...

 

The Performance Plus is too expensive, will talk to VB&P on Monday to check with their tech guy but I think is going to be the Street&Slalom with upgraded struts rods as ddawson suggested.

 

I was wondering about the discrepancy in 550# front coil spring. My kit said that as sold it would lower my front end one inch. Which it did and I added a 3/8ths spacer to get it to where I wanted it. I'm thinking that maybe later VB&P 550# might have been stock height and that why some of the posters were cutting coils.

I've always felt that poly bushings were the best. they are hard enough to only have minor compression. Where as real race cars use metal on metal heim joints. I just run mine at the lowest point on the cam and for rear shock I use the QA-1 dual adjusts.

VB&P will swap items on the kits. You might ask about a 9/16th smaller rear sway or even 5/8th instead of the listed 3/4. Mine has spring end links front and rear so you can set them to not come into play until you have major wheel vertical movement

 

That's interesting, why would I want a smaller rear sway? Does it oversteer too much with 3/4" or is about ride quality?

I will also check if the kit comes with poly bushing or rubber, it doesn't say on the kits page but it states that the front is lowered 3/4".

 

All SBC C3 corvettes will understeer at the limit with factory suspension. The base suspension corvettes have no rear bar and will understeer much when pushed. Even the gymkhana cars with the 7/16 inch GM STYLE rear bar (not the rear sway bars that come in kits which are not the GM designed rear sway bar endlinks) will understeer, but less so than the base suspension cars. Using a 3/4 inch NON GM STYLE rear bar can induce snap oversteer which is the reason some recommend a smaller non factory rear style sway bar.

In my post #8 above, I do use a bigger rear sway bar 3/4 inch BUT it is a GM STYLE designed rear sway bar and I do have a modified gymkhana suspension on my car in place of the OEM 7/16 inch rear bar. I would recommend a 7/16 inch GM rear bar or maybe the 9/16 inch rear GM bar (BB C3's) but would stay away from the NON factory NON GM rear sway bars. If you are intent on a non factory GM style bar, then I would definitely go smaller AND use adjustable end link bushings that allow more movement of the trailing arm, FWIW....

 

I have a big block car with a rear sway bar. The OEM linkage allows good articulation compared to the non OEM setups.

This shot isn't hooked up into the trailing arm but you can see the two pivot points.

 

This is an old picture with the rear tires up off the ground. 420# rear mono, Koni shocks, spring end links. This was a very short test and I took off the Koni shocks and 420# mono. VB&P made me a custom mono rear spring with 520#

 

Today I pulled the wheels and checked my rotors when I found this sticker concealed on the rear suspension. Its hard to say how many years ago this was upgraded.