First Generation Firebird
Posted By: Dr. Drivability Front Springs - 02/15/21 03:33 PM
I know this subject has been warmed over many times, but looking for actually experience with purchase (where?), install and correct ride height.

Need to replace the 52 year old worn out springs and don't want any ride height surprises or issues.

'68 350 convertible no A/C.
Posted By: ramair68 Re: Front Springs - 02/15/21 03:45 PM
I tried the Moog springs and they were too tall. Ended up with the Eatons, gave my car a nice stance IMO. Quality wise they are probably both the same, Eaton will give you the specs, their springs are I believe $50-60 more. Pay attention and mark the originals as orientation will affect ride height. Also if the factory added cushions you might have to reuse them to keep side to side equal. Plan on leaving your tools "out" after install, cause you may have to redo things a few times to your own personal preference and liking. One more thing...remember to lean on the front bumper and push down a few times to get the new springs to seat before judging the ride height.
Posted By: Bob S. Re: Front Springs - 02/15/21 07:17 PM
As far as front springs, I would suggest going though Ames. Both Ames and Eaton sell the same Moog front coil springs and you might have a better chance getting the correct ones from Ames since they know pontiacs specifically. The front springs I got from Ames 15 years ago worked out pretty well on my 67 firebird vert. I had a bad time with Eaton getting the correct front springs for my 69 GTO vert. They sold me Moog springs that were comically way too tall and wouldn't believe me that they were wrong. I had to force them to take them back and send hardtop springs that were much closer to correct. So they are continuing to sell the wrong springs to unsuspecting GTO/LeMans vert customers. I'm still pissed at Eaton.

I would also suggest making sure you really need new springs before you go down this path. Changing front springs is not fun and somewhat dangerous and you could end up with a ride height you don't like.
Posted By: FirebirdMike Re: Front Springs - 02/17/21 02:30 PM
Originally Posted by Bob S.
I would also suggest making sure you really need new springs before you go down this path. Changing front springs is not fun and somewhat dangerous and you could end up with a ride height you don't like.


This is true. Coil springs do not wear if installed correctly. At most, they'll have some creep which drops ride height slightly over time, but spring rate itself will not change. (Which can be why some are surprised if they replace well aged springs with new, and the vehicle sits a bit higher. Or so-called "lowering springs" end up at the same ride height). And coil springs should not fatigue if made correctly (or some idiot hasn't hit them with a torch).

The only reason to change springs is if you want a different ride height, you've changed something that adds/reduces weight significantly, or you want to change the handling characteristics (e.g. higher spring rate for performance, at the sacrifice of ride quality).

Leaf springs are different story.
Posted By: Dr. Drivability Re: Front Springs - 02/17/21 05:04 PM
Originally Posted by FirebirdMike
Originally Posted by Bob S.
I would also suggest making sure you really need new springs before you go down this path. Changing front springs is not fun and somewhat dangerous and you could end up with a ride height you don't like.


This is true. Coil springs do not wear if installed correctly. At most, they'll have some creep which drops ride height slightly over time, but spring rate itself will not change. (Which can be why some are surprised if they replace well aged springs with new, and the vehicle sits a bit higher. Or so-called "lowering springs" end up at the same ride height). And coil springs should not fatigue if made correctly (or some idiot hasn't hit them with a torch).

The only reason to change springs is if you want a different ride height, you've changed something that adds/reduces weight significantly, or you want to change the handling characteristics (e.g. higher spring rate for performance, at the sacrifice of ride quality).

Leaf springs are different story.


Interesting, I've never heard this, but never really thought about it too much either. Makes sense though when you see posts of before and after and the ride height is not what was desired and guys end up doing the job twice or cutting out coils. So, sounds like a shouldn't worry about 52 year old original springs.
Posted By: barnbird Re: Front Springs - 02/18/21 07:04 PM
I completely agree with what Bob S. said as I have seen this play out as a mechanic over the years with customers, friends, as well as my own cars. sometimes because the new springs are just so far off and sometimes because they just didn't meet a particular persons expectations. If you like the look of the ride height now that is half the battle but unfortunately coils can sag enough over the years to cause ride and handling problems. This is usually directly related with original springs to miles and how well the car was maintained back in it's daily driver days. after years spent working under a lift the biggest culprit being old spent shocks. All you have to do is cut an old shock apart and see the piss that comes out that used to be oil to understand that it's not just leaking seals that condemn shocks. The shocks job is not only ride comfort but to limit spring jounce and body roll. Weak shocks left on our old used cars back in the day accelerated spring wear tremendously. All that said you need to look under the car while on the ground or a 4 post lift and look to see if your lower control arms and bottoming bumpers are roughly in the right positions. The lower control arm should sit either level from frame connection to ball joint or slightly lower at the ball joint end. also look at the space between the bottoming bumper and it's stop and there should be a decent gap. if everything looks decent but the bottoming bumper looks pretty pounded up you need shocks. Also if the ball joint end of the arm sits higher than the frame end you need springs. Of course if you want to be fussy you could measure ride height but with the above method there is no need to.
Posted By: Banshee Re: Front Springs - 02/20/21 06:41 AM
I work a mile from Eaton Spring off Michigan Ave in Detroit. Done business with them many times over the years.

LMK if there is any thing I can do to assist.
Posted By: Beardog Re: Front Springs - 02/23/21 01:53 PM
I took my 68 into a shop 2 years ago and they installed new progressive springs, when I went to get it I was a little pissed, the front sit up very high, looked like a gasser, they said it would drop a little, so a week later I order new leaf springs for the back since they were original also, and installed them, leveled out the car, sits a little higher but I like it..

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Posted By: Bob S. Re: Front Springs - 02/23/21 06:41 PM
Maybe the best course is tubular A arms and coil overs. You can adjust the height right where you want it
Posted By: Dr. Drivability Re: Front Springs - 02/23/21 08:27 PM
Appreciate all the responses, I like the stance I currently have. Think I'm gonna go with some new shocks to start with.

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