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Stock style progressive spring install observations
I am in the process of reinstalling the front suspension on my 71 LT-1 following restoration. I have a set of "correct" reproduction progressive coils springs (SU12V) purchased front a good reputable vendor. The top 4 coils are wound much closer and I installed these at the top in the spring pocket per the AIM. Once I completed the first spring install and removed the spring compressor I am inspecting everything and I notice those four close coils up in the pocket are damn near touching each other i.e. very small gap between those coils.
I would sure like to hear from anyone that has installed either the reproduction or the OE springs and observed the installed gap between those top coils.
I would tend to say that the spring is too long like most stock type springs. You are better off and it is much safer to R&R one inch shorter springs. I did the front end bushings on a stock 68 and whit the A-arm down the spring still made contact with the top and bottom and was firmly in place
I would tend to say that the spring is too long like most stock type springs. You are better off and it is much safer to R&R one inch shorter springs. I did the front end bushings on a stock 68 and whit the A-arm down the spring still made contact with the top and bottom and was firmly in place
True, I have closeup pics of installed oem springs but it will be an hour before I can post them.
UPDATE: Photobucket deleted the coil spring pics when they "re-organized their site"
Last edited by doorgunner; Jun 23, 2021 at 10:23 PM.
I am in the process of reinstalling the front suspension on my 71 LT-1 following restoration. I have a set of "correct" reproduction progressive coils springs (SU12V) purchased front a good reputable vendor. The top 4 coils are wound much closer and I installed these at the top in the spring pocket per the AIM. Once I completed the first spring install and removed the spring compressor I am inspecting everything and I notice those four close coils up in the pocket are damn near touching each other i.e. very small gap between those coils.
I would sure like to hear from anyone that has installed either the reproduction or the OE springs and observed the installed gap between those top coils.
With the suspension dropped/unloaded....the springs will arc from the control arm to the upper spring pocket.....it is normal, once it is on the ground....it straightens out.
FYI.....in over 30 year of my Dad and I playing with these cars......I have yet to see an off the shelf coil that didn't make the car sit too high in the front......most all needed one coil cut.
Lowering springs are an option but I have never had any so it is easier for me to get $80 Moog pieces and take a coil off........
You see restored sky high Vette's all of the time.....and this is the reason why.....and to me, spending all that time restoring a car and having it sit like a 4x4 just kills it......not to mention it will handle like **** and the frontend will lift at like 110 mph.......
With the suspension dropped/unloaded....the springs will arc from the control arm to the upper spring pocket.....it is normal, once it is on the ground....it straightens out.
FYI.....in over 30 year of my Dad and I playing with these cars......I have yet to see an off the shelf coil that didn't make the car sit too high in the front......most all needed one coil cut.
Lowering springs are an option but I have never had any so it is easier for me to get $80 Moog pieces and take a coil off........
You see restored sky high Vette's all of the time.....and this is the reason why.....and to me, spending all that time restoring a car and having it sit like a 4x4 just kills it......not to mention it will handle like **** and the frontend will lift at like 110 mph.......
Jebby
Absolutely 100% correct. I have the 500 pound springs that supposedly sit an inch lower and I cut 3\4 of a cool and it looks alot better and on the highway it's great at speed plus it rides well.
I really think that those big long stock springs are actually dangerous to R&R. The one inch shorter 550 and 460 are so easy to take in and out without spring compressors
My OEM coil springs cause the wheel well arch to be 30" from the garage floor (3" gap between wheel & fender arch.
Because I wanted a smooth ride for long road trips I cut exactly two coils off the tightly wound end.
That lowered the fender arch to 28 1/4" which visually looked much better than the "4 X 4 Look".
Since the ride is smoother I will add a front sway bar to reduce the small amount of "lean" when driving on curvy roads.
IF I remember correctly...the tighter coils were less than 1/2" apart after the full weight of the car was placed on them (rebuilt 350 SBC/aluminum radiator/(28" diameter tires)225 70-15 x 8" wide rims).
The wheel well arch has a 1" gap above the new wheels.
Also...the coil springs were easier to install into the pockets by using a pry bar, and there was less "bow" in the springs while jacking the lower a-arm into place.
Last edited by doorgunner; Jun 24, 2021 at 02:52 PM.
Thanks for all of the replies. After your feedback and laying under car taking a second, third and fourth look, I decided not to use these OEM reproduction springs. Those upper coils are approximately 1/4" or less gap. I would never be satisfied leaving them installed and they are way to difficult to wrangle in and out should I want to adjust the ride height later on. So I bit the bullet and removed it this afternoon. I'm thinking I will go with a 474 lb 7 coil spring that is 13 inches long vs. the 16.5 inch 10 coil OE spring. "Similar to the F41 design spring"
Stock style progressive spring install observations
