# 68 gto front springs AC vs. non-AC ? HELP!



## perrystroke (Nov 17, 2014)

68 GTO CONVERTIBLE. I found a great deal on front springs but they are for GTO convertibles with air cond. but mine doesn't have air cond. So what Im asking is that can I use them on my GTO? and what is the difference between the ac springs and non ac springs. they are MOOG springs btw.


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## jmt455 (Mar 26, 2012)

The A/C springs are designed to maintain the specified ride height with the extra weight of the air conditioning system.

If you use A/C springs on a non-A/C car, the car will sit higher than the stock ride height.


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## perrystroke (Nov 17, 2014)

jmt455 said:


> The A/C springs are designed to maintain the specified ride height with the extra weight of the air conditioning system.
> 
> If you use A/C springs on a non-A/C car, the car will sit higher than the stock ride height.


how much higher are you talking ?


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## jmt455 (Mar 26, 2012)

I don't know, but I would call MOOG customer service/tech support.
They should be able to tell you exactly how those springs will behave on a non-AC car.


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## Matthew (Feb 11, 2011)

I have coil springs for a 68 with AC on my 68 without AC. I don't think the actual ride height is different - just my opinion as I have never measured a new set of non AC springs installed. If it is different, it can't be much. I would suspect, again only my opinion here, the ride is just a little bit stiffer. Matt


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## PontiacJim (Dec 29, 2012)

Checked the factory specs I have on the '68 models. All front springs are 11.30" tall with a 3.6" ID. The difference is in the spring rate in pounds, 250, 280, 310 & 335 depending on what body type, engine, or options. The factory specs do not tell me what this breaks down to, however, it appears under the column for GTO is the 310 rated spring. It is possible with the extra weight of air conditioning, the car used the 335 rated spring.

So, that said, it would appear that all springs are of the same installed height, so it should not affect ride height. The difference would then be the firmness of the ride based on the higher spring rates.:thumbsup:


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## perrystroke (Nov 17, 2014)

PontiacJim said:


> Checked the factory specs I have on the '68 models. All front springs are 11.30" tall with a 3.6" ID. The difference is in the spring rate in pounds, 250, 280, 310 & 335 depending on what body type, engine, or options. The factory specs do not tell me what this breaks down to, however, it appears under the column for GTO is the 310 rated spring. It is possible with the extra weight of air conditioning, the car used the 335 rated spring.
> 
> So, that said, it would appear that all springs are of the same installed height, so it should not affect ride height. The difference would then be the firmness of the ride based on the higher spring rates.:thumbsup:


I would rather have firm front suspension over the front being higher than it already is. So with that being said, what would you do? I will be calling moog tech tomorrow to get the lowdown from them directly also.


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## Matthew (Feb 11, 2011)

I recommend the w/AC springs. Matt


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## 666bbl (Apr 13, 2014)

A/C springs can take a 1/2 coil cut to lower the car because of the rate. I cut a full coil on an iron head BBC in an F body. They were A/C springs and yet the static ht was almost 2" lower. The best part was all of the "stored energy" due to the in/lb rating. It stood up really fast at the track, of course assisted with 90/10 shocks. The ride quality was really nice on rough return roads but I wouldn't recommend it for driving around town. At least not my town. MI, and more specific, S.E. MI roads absolutely suck. 2 seasons here, winter and construction.


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## Sixty7GTO (May 4, 2017)

Pontiac Jim,
Would you have the specs on a 67 GTO with A/C?


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## PontiacJim (Dec 29, 2012)

Sixty7GTO said:


> Pontiac Jim,
> Would you have the specs on a 67 GTO with A/C?



I am showing 4 different spring part numbers for non-A.I.R. equipped cars. 

Part numbers for the Coupe & HT, manual trans. without AC is 388283. 
Coupe & HT manual trans with AC & the Convert/Auto without AC use 386288. 
Convertible with manual trans. without AC used 384752 and with AC 388284. 
Automatic HT & Coupe/Auto without AC used 384752. 
Automatic Coupe, HT, & Convertible with AC all used 388284.

Found this spec for the Moog replacement springs for 386288 - 
Bar Diameter - Inches	0.65
End Type 1	Tangential
End Type 2	Tangential
Free Height - Inches	17.99
ID - Inches	3.63
Installation Height - Inches	11.00
Load - lbs	2279.00
Spring Rate - lbs per inch	327.00
Spring Type	Constant Rate 

Could not find anything for the Automatic w/AC 388284 with regards to specs. OPGI lists a pair that should work keeping in mind that all Automatic w/AC used the same springs: https://www.opgi.com/gto/TRW5272/

You can also do a search of past postings which will give you the names of those companies that can custom make the springs per the specs of the 388284 spring if you have these.

The AMA specs for the 1967 Tempset/Lemans/GTO will list the spring rates in lbs per inch only and not any other specs and they do not show if specific to AC or not. https://www.ebay.com/itm/1967-Ponti...974653?hash=item43b9eab17d:g:JeIAAOxySOlSAnHc


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## Pinion head (Jan 3, 2015)

Coil Spring Specialties has all the factory spec sheets. These include wire gauge, free length, & number of coils. 
CSS can also spec custom coils springs for custom ride heights & for vehicles that have had significant weight removal from the front of the car.

Coil Spring Specialties


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## Abinder (Mar 8, 2021)

PontiacJim said:


> Checked the factory specs I have on the '68 models. All front springs are 11.30" tall with a 3.6" ID. The difference is in the spring rate in pounds, 250, 280, 310 & 335 depending on what body type, engine, or options. The factory specs do not tell me what this breaks down to, however, it appears under the column for GTO is the 310 rated spring. It is possible with the extra weight of air conditioning, the car used the 335 rated spring.
> 
> So, that said, it would appear that all springs are of the same installed height, so it should not affect ride height. The difference would then be the firmness of the ride based on the higher spring rates.👍


Where would I find the location of these factory specs you speak of?


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## PontiacJim (Dec 29, 2012)

Abinder said:


> Where would I find the location of these factory specs you speak of?


Read Post #7, AMA Specs and click on the highlighted links and you should be able to search around and find the AMA specs for your car.









FAQ - General: GTO and Pontiac Reference Sources


Surprised this has not been brought up - a suggested reading list for us Pontiac enthusiasts. Let's list any books, journals, factory literature, CD's, or other printed materials tht may be of value. And, it does not have to necessarily be Pontiac specific if it can be applied to out hobby...




www.gtoforum.com


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