mrichi

Hi I've installed a VB&P 420 composite rear spring ,but I am struggling to get enough ride height into the rear end , even with the spring bolts screwed right up the height from the ground to the lip of the wheel arch is 68cm not sure what I am doing wrong

Does anyone have a photo of a VB&P composite rear spring installed on their car

leadfoot4

How long are your spring bolts? IIRC, the stock length is around 8" in length, and guys wanting to lower their cars, run 10" long bolts.

Metalhead140

Your might be thinking c4? Stock c3 bolts are ~6", and 8" bolts are normally used for lowering, occasionally 10" but they may have clearance issues.

C3 Stroker

I have the VBP 380 composite rear spring..... see my sig picture...

Paul L

Here is a #330. The stock bolts are just over 6". Those in the pic are 8".

"Spring bolts are screwed right up." Do you mean that the nuts on the bolts are at the top of the thread travel?

mrichi

Yes i've had to screw the nut to the top of the thread travel and even doing that the rear of the car is only just high enough

CheezMoe

Sounds to me like maybe the spring is upside down. Most complain they can't get low enough. Paul's pic is correct with 8" bolts mine looks the about the same and have 28 1/2" at center wheel well.

Good luck!

TOM B1

post a pic of your spring. some composites require a thick spacer between the spring and rear end mount to raise the ride height.

leadfoot4

Yeah, maybe....it's been a while since I've worked on a C-3.

mrichi

Finally have photos the spring is a new VB&P 420 car is a 79 Corvette with a 454 big block .As the photo shows ive had to screw the spring bolt nut almost right up to the top of the thread to get a reasonable ride height . I can't work out whats wrong , should the spring be curved up at the ends as the photo shows hotos

jkippin

that spring looks to be installed correctly. Looking at the photo is it a shadow or could the spring be cracked in the middle of the center mount?

mrichi

I think it's just some sticky material from packaging ,but I will have a closer look at it thank you

Dodosmike

Looks right to me as well. I'll try and find some pics of my '78 rear spring install to compare.

The reason the spring looks like its "up" at the ends is because the nuts on the spring bolt are pushing it up, as you stated earlier.

Was the car ever hit in the back end?
How long are the bolts overall?
Are the half shafts fairly level or are they noticeably higher on either end?
Is the spring "new" or did you buy a used spring? Could it be possibly mis-labeled and not a 420?

edit:
Still on the wrecked parts car before I put it on the driver car.



I don't have a pic of mount in the middle for some reason.

jkippin

If I remember correctly VBP gives you a rough pre adjustment measurement of 1.25 inches of thread showing on the supplied bolts with new springs. You are clearly beyond that.
Here is a dual mount VBP spring but the threads on the bolts are in the same location as to when it had the single mount spring. Rear height is 27.0

wendellp601

When I compare your photos to the one that Paul74 posted, there seems to be a difference in the way your spring tapers down at the end. His looks like the taper is on top of the spring, and yours appears to have the taper on the bottom.

jkippin

pull the spring out and check it. The curved part should be down. the rubber mount should be on the top ,against the differential mounting point and the metal tips on the end of the spring should be on the bottom of the spring.
If the spring is brand new maybe someone assembled it upside down by mistake.

Neil B

This does not look right to me at all. The spring should be tapering down, not up.

claysmoker

Flip the spring over.

keithinspace

You can't just 'flip the spring over' since the metal stuff is installed by VB&P and it can only be installed one way.

THAT SAID, something looks totally wrong about that picture. No way in the world should it be that close to the trailing arm. There needs to be some 'bolt' there to allow things to move around as the suspension flexes. And I don't like how the end of the spring is pointed to the sky. It should be flat or pointed slightly down.

Either you got a totally bum spring (something jacked inside it) or VB&P installed the metal widgets at the end of the spring upside down.

Whatever the case, that isn't right. I would not drive my car like that.

7t9l82

Sure looks inverted to me. I think those ends bolt on call VBP and ask if that's the case.