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I am working the front suspension for new ball joints and control arm bushings. The first spring is out. How can I tell if I need a new spring? This looks fine, to obvious sag, no rust.
If you are concerned about it, I would measure the length to make sure they are both the same, but otherwise not likely to be a problem. If they fail it is usually by breaking.
Only reason would be to upgrade performance from original. OEM’s were either 460lb springs or 550 for Gymkana option. 550’s would require matching rear spring/shocks and change the ride quality. Cutting one coil off original 460’s lowers the front end 1” and stiffens the ride just a little. Dual rate 480/700 coils by Hyperco lower the front end 1” as well and improve handling, but keep the ride quality of the softer springs and match well with original rear spring and most shocks. Add a spreader bar in front and you’ll have much better handling than the original 460 coils. Going around curves and corners faster with less body roll is always more fun. This minimal change runs about $300 for coils and spreader bar.
Charlie
I am rebuilding the a arms and replacing the original 550's because one looked crooked, only a $150 investment. Great idea about the spreader bar. My Gymkana original suspension was never to harsh but of course I am not the original owner and not sure how many miles are on it. I will be going with HD bilstiens on the front and Sports on the back.
Only reason would be to upgrade performance from original. OEM’s were either 460lb springs or 550 for Gymkana option. 550’s would require matching rear spring/shocks and change the ride quality. Cutting one coil off original 460’s lowers the front end 1” and stiffens the ride just a little. Dual rate 480/700 coils by Hyperco lower the front end 1” as well and improve handling, but keep the ride quality of the softer springs and match well with original rear spring and most shocks. Add a spreader bar in front and you’ll have much better handling than the original 460 coils. Going around curves and corners faster with less body roll is always more fun. This minimal change runs about $300 for coils and spreader bar.
Charlie
Where did you come up with those bogus big numbers for OEM springs? Could you post a link to these 480/700 coils by Hyperco?
To the other poster, Springs actually loose tension compared to new within 10 - 15 years. I've done lots of Vette spring over the years at the shop.
From: Loud, Raw and Dangerous 1968 327 4S in Southern California
I had to replace my front springs. Car rode like crap. Previous owner had tried to lower the car by heating and deforming them. It was quite obvious as the coils were not evenly spaced and some were at an odd angle.
Last edited by Redvette2; Jun 2, 2023 at 11:17 AM.
Reason: Kant spel
Where did you come up with those bogus big numbers for OEM springs? Could you post a link to these 480/700 coils by Hyperco?
To the other poster, Spring actually loose tension compared to new within 10 - 15 years. I've done lots of Vette spring over the years at the shop.
The spring ratings are what is being sold as original replacements from parts venders; generally two choices. Here’s Corvette Central’s offerings(F41 option=550). My mistake if actual originals are different from what’s being sold today.
480/700’s are from Ridetech. Ad says -2”; I only got -1”. But, that was replacing 42 year old springs.
Charlie
Only reason would be to upgrade performance from original. OEM’s were either 460lb springs or 550 for Gymkana option. 550’s would require matching rear spring/shocks and change the ride quality. Cutting one coil off original 460’s lowers the front end 1” and stiffens the ride just a little. Dual rate 480/700 coils by Hyperco lower the front end 1” as well and improve handling, but keep the ride quality of the softer springs and match well with original rear spring and most shocks. Add a spreader bar in front and you’ll have much better handling than the original 460 coils. Going around curves and corners faster with less body roll is always more fun. This minimal change runs about $300 for coils and spreader bar.
Charlie
Here is my collection of 24 different spring data available for the C2 and C3 Corvettes. Mostly GM. Basically only aftermarket ones left now. I fully suspect the CC and VBP springs are just reboxed Moogs. I think Moog actually makes springs. or maybe they just get them from Eaton. I know they actually make springs. Doesn't matter. End result is there are only a few available new nowdays.
Last edited by leigh1322; Jun 2, 2023 at 05:00 PM.
On re-reading charts and ads the 460 springs are sold as ‘grand touring’; stiffer than OEM. OEM being less than 300, and varying. F41 is listed as 550 on both charts and ads. Impressive difference between base and F41 springs!
Charlie
66 SB springs were as light as 195#
Data says my 72 BB springs are 284#.
But my calculations put them even heavier than that at ride height, around 330#.
They are progressive rate springs, and so the math is much more complicated than what you will find on the internet.
Since they are practically impossible to measure directly, who knows what they really are.
This is what I came up with for my factory springs. There is a small change in spring rate during normal spring / suspension travel. By the time the rate starts increasing significantly, the suspension bottoms out.
Last edited by leigh1322; Jun 2, 2023 at 05:54 PM.
I have a new set of moog 5758 springs as well as a new rear gymkhana spring and a new set both rubber and poly bushings if anyone is looking... I went with tubular a arms and coil overs after buying everything.. I also have new upper and lower ball joints I wont be using.
The springs being sold today are made with a different process ive been told and the result is a shorter spring with superior performance.
On re-reading charts and ads the 460 springs are sold as ‘grand touring’; stiffer than OEM. OEM being less than 300, and varying. F41 is listed as 550 on both charts and ads. Impressive difference between base and F41 springs!
Charlie
Yes, these are the real numbers. After market springs are so much better because they are shorter and stiffer. Making them safer and easier to install. The dual rate 400/700 might be nice for smooth riding and the ability to not bottom out.
FRONT SPRINGS
327/350 (no A/C) - Part #3931823 - "HS" - 250 lbs/in 327/350 (with A/C) - Part #3931824 - "HT" - 264 lbs/in 427/454 (no A/C) - Part #3931825 - "HU" - 284 lbs/in 427/454 (with A/C) - Part #3931826 - "HV" - 325 lbs/in F41 (all) - Part #3832518 - "EA" - 550 lbs/in
After market springs are so much better because they are shorter and stiffer. Making them safer and easier to install.
A 65 stock spring when compared to an aftermarket spring has a huge height difference. Use a jackscrew or threaded rod through the shock tower to compress the spring for easy installation.
If it was me and I liked the height of my ride (which I do), when I got the springs out I would just have them and the control arms blasted and powder coated.
If it was me and I liked the height of my ride (which I do), when I got the springs out I would just have them and the control arms blasted and powder coated.
You can’t sandblast springs. It alters the temper of the steel.
Replace Front Springs??
A 65 stock spring when compared to an aftermarket spring has a huge height difference. Use a jackscrew or threaded rod through the shock tower to compress the spring for easy installation. 
